Monday, December 22, 2008

Loading Image Script

body oninit="init()" onload="init()"
div id="loading" style="position:absolute; width:100%; text-align:center; top:299px; left: 0px;">script>
var ld=(document.all);

var ns4=document.layers;
var ns6=document.getElementById&&!document.all;
var ie4=document.all;

if (ns4)
ld=document.loading;
else if (ns6)
ld=document.getElementById("loading").style;
else if (ie4)
ld=document.all.loading.style;

function init()
{
if(ns4){ld.visibility="hidden";}
else if (ns6||ie4) ld.display="none";
}
script

Sunday, December 21, 2008

Email etiquette

It is amazing to find that in this day and age, some companies have still not realized how important their email communications are. Many companies send email replies late or not at all, or send replies that do not actually answer the questions you asked. If your company is able to deal professionally with email, this will provide your company with that all important competitive edge. Moreover by educating employees as to what can and cannot be said in an email, you can protect your company from awkward liability issues. This website discusses the main etiquette rules and provides advice on how employers can ensure that they are implemented.
'By requiring employees to use appropriate, businesslike language in all electronic communications, employers can limit their liability risks and improve the overall effectiveness of the organization's e-mail and Internet copy in the process' - Excerpt from 'Writing Effective E-mail', by Nancy Flynn and Tom Flynn.
Why do you need email etiquette?
What are the email etiquette rules?
How do you enforce email etiquette?
Why do you need email etiquette?
A company needs to implement etiquette rules for the following three reasons:
Professionalism: by using proper email language your company will convey a professional image.
Efficiency: emails that get to the point are much more effective than poorly worded emails.
Protection from liability: employee awareness of email risks will protect your company from costly law suits.

What are the etiquette rules?
There are many etiquette guides and many different etiquette rules. Some rules will differ according to the nature of your business and the corporate culture. Below we list what we consider as the 32 most important email etiquette rules that apply to nearly all companies.
32 most important email etiquette tips:
1. Be concise and to the point
2. Answer all questions, and pre-empt further questions
3. Use proper spelling, grammar & punctuation
4. Make it personal
5. Use templates for frequently used responses
6. Answer swiftly
7. Do not attach unnecessary files
8. Use proper structure & layout
9. Do not overuse the high priority option
10. Do not write in CAPITALS
11. Don't leave out the message thread
12. Add disclaimers to your emails
13. Read the email before you send it
14. Do not overuse Reply to All
15. Mailings > use the bcc: field or do a mail merge
16. Take care with abbreviations and emotions
17. Be careful with formatting
18. Take care with rich text and HTML messages
19. Do not forward chain letters
20. Do not request delivery and read receipts
21. Do not ask to recall a message.
22. Do not copy a message or attachment without permission
23. Do not use email to discuss confidential information
24. Use a meaningful subject
25. Use active instead of passive
26. Avoid using URGENT and IMPORTANT
27. Avoid long sentences
28. Don't send or forward emails containing libelous, defamatory, offensive, racist or obscene remarks
29. Don't forward virus hoaxes and chain letters
30. Keep your language gender neutral
31. Don't reply to Spam
32. Use cc: field sparingly

1. Be concise and to the point.
Do not make an e-mail longer than it needs to be. Remember that reading an e-mail is harder than reading printed communications and a long e-mail can be very discouraging to read.

2. Answer all questions, and pre-empt further questions.
An email reply must answer all questions, and pre-empt further questions – If you do not answer all the questions in the original email, you will receive further e-mails regarding the unanswered questions, which will not only waste your time and your customer’s time but also cause considerable frustration. Moreover, if you are able to pre-empt relevant questions, your customer will be grateful and impressed with your efficient and thoughtful customer service. Imagine for instance that a customer sends you an email asking which credit cards you accept. Instead of just listing the credit card types, you can guess that their next question will be about how they can order, so you also include some order information and a URL to your order page. Customers will definitely appreciate this.

3. Use proper spelling, grammar & punctuation.
This is not only important because improper spelling, grammar and punctuation give a bad impression of your company, it is also important for conveying the message properly. E-mails with no full stops or commas are difficult to read and can sometimes even change the meaning of the text. And, if your program has a spell checking option, why not use it?

4. Make it personal.
Not only should the e-mail be personally addressed, it should also include personal i.e. customized content. For this reason auto replies are usually not very effective. However, templates can be used effectively in this way, see next tip.

5. Use templates for frequently used responses.
Some questions you get over and over again, such as directions to your office or how to subscribe to your newsletter. Save these texts as response templates and paste these into your message when you need them. You can save your templates in a Word document, or use pre-formatted emails. Even better is a tool such as Reply Mate for Outlook (allows you to use 10 templates for free).

6. Answer swiftly.
Customers send an e-mail because they wish to receive a quick response. If they did not want a quick response they would send a letter or a fax. Therefore, each e-mail should be replied to within at least 24 hours, and preferably within the same working day. If the email is complicated, just send an email back saying that you have received it and that you will get back to them. This will put the customer's mind at rest and usually customers will then be very patient!

7. Do not attach unnecessary files.
By sending large attachments you can annoy customers and even bring down their e-mail system. Wherever possible try to compress attachments and only send attachments when they are productive. Moreover, you need to have a good virus scanner in place since your customers will not be very happy if you send them documents full of viruses!

8. Use proper structure & layout.
Since reading from a screen is more difficult than reading from paper, the structure and lay out is very important for e-mail messages. Use short paragraphs and blank lines between each paragraph. When making points, number them or mark each point as separate to keep the overview.

9. Do not overuse the high priority option.
We all know the story of the boy who cried wolf. If you overuse the high priority option, it will lose its function when you really need it. Moreover, even if a mail has high priority, your message will come across as slightly aggressive if you flag it as 'high priority'.

10. Do not write in CAPITALS.
IF YOU WRITE IN CAPITALS IT SEEMS AS IF YOU ARE SHOUTING. This can be highly annoying and might trigger an unwanted response in the form of a flame mail. Therefore, try not to send any email text in capitals.

11. Don't leave out the message thread.
When you reply to an email, you must include the original mail in your reply, in other words click 'Reply', instead of 'New Mail'. Some people say that you must remove the previous message since this has already been sent and is therefore unnecessary. However, I could not agree less. If you receive many emails you obviously cannot remember each individual email. This means that a 'thread less email' will not provide enough information and you will have to spend a frustratingly long time to find out the context of the email in order to deal with it. Leaving the thread might take a fraction longer in download time, but it will save the recipient much more time and frustration in looking for the related emails in their in box!

12. Add disclaimers to your emails.
It is important to add disclaimers to your internal and external mails, since this can help protect your company from liability. Consider the following scenario: an employee accidentally forwards a virus to a customer by email. The customer decides to sue your company for damages. If you add a disclaimer at the bottom of every external mail, saying that the recipient must check each email for viruses and that it cannot be held liable for any transmitted viruses, this will surely be of help to you in court (read more about email disclaimers). Another example: an employee sues the company for allowing a racist email to circulate the office. If your company has an email policy in place and adds an email disclaimer to every mail that states that employees are expressly required not to make defamatory statements, you have a good case of proving that the company did everything it could to prevent offensive emails.

13. Read the email before you send it.
A lot of people don't bother to read an email before they send it out, as can be seen from the many spelling and grammar mistakes contained in emails. Apart from this, reading your email through the eyes of the recipient will help you send a more effective message and avoid misunderstandings and inappropriate comments.

14. Do not overuse Reply to All.
Only use Reply to All if you really need your message to be seen by each person who received the original message.

15. Mailings > use the Bcc: field or do a mail merge.
When sending an email mailing, some people place all the email addresses in the To: field. There are two drawbacks to this practice: (1) the recipient knows that you have sent the same message to a large number of recipients, and (2) you are publicizing someone else's email address without their permission. One way to get round this is to place all addresses in the Bcc: field. However, the recipient will only see the address from the To: field in their email, so if this was empty, the To: field will be blank and this might look like spamming. You could include the mailing list email address in the To: field, or even better, if you have Microsoft Outlook and Word you can do a mail merge and create one message for each recipient. A mail merge also allows you to use fields in the message so that you can for instance address each recipient personally. For more information on how to do a Word mail merge, consult the Help in Word.

16. Take care with abbreviations and emotions.
In business emails, try not to use abbreviations such as BTW (by the way) and LOL (laugh out loud). The recipient might not be aware of the meanings of the abbreviations and in business emails these are generally not appropriate. The same goes for emotions, such as the smiley :-). If you are not sure whether your recipient knows what it means, it is better not to use it.

17. Be careful with formatting.
Remember that when you use formatting in your emails, the sender might not be able to view formatting, or might see different fonts than you had intended. When using colors, use a color that is easy to read on the background.

18. Take care with rich text and HTML messages.
Be aware that when you send an email in rich text or HTML format, the sender might only be able to receive plain text emails. If this is the case, the recipient will receive your message as a .txt attachment. Most email clients however, including Microsoft Outlook, are able to receive HTML and rich text messages.

19. Do not forward chain letters.
Do not forward chain letters. We can safely say that all of them are hoaxes. Just delete the letters as soon as you receive them.

20. Do not request delivery and read receipts.
This will almost always annoy your recipient before he or she has even read your message. Besides, it usually does not work anyway since the recipient could have blocked that function, or his/her software might not support it, so what is the use of using it? If you want to know whether an email was received it is better to ask the recipient to let you know if it was received.

21. Do not ask to recall a message.
Biggest chances are that your message has already been delivered and read. A recall request would look very silly in that case wouldn't it? It is better just to send an email to say that you have made a mistake. This will look much more honest than trying to recall a message.

22. Do not copy a message or attachment without permission.
Do not copy a message or attachment belonging to another user without permission of the originator. If you do not ask permission first, you might be infringing on copyright laws.

23. Do not use email to discuss confidential information.
Sending an email is like sending a postcard. If you don't want your email to be displayed on a bulletin board, don't send it. Moreover, never make any libelous, sexist or racially discriminating comments in emails, even if they are meant to be a joke.

24. Use a meaningful subject.
Try to use a subject that is meaningful to the recipient as well as yourself. For instance, when you send an email to a company requesting information about a product, it is better to mention the actual name of the product, e.g. 'Product A information' than to just say 'product information' or the company's name in the subject.

25. Use active instead of passive.
Try to use the active voice of a verb wherever possible. For instance, 'We will process your order today', sounds better than 'Your order will be processed today'. The first sounds more personal, whereas the latter, especially when used frequently, sounds unnecessarily formal.

26. Avoid using URGENT and IMPORTANT.
Even more so than the high-priority option, you must at all times try to avoid these types of words in an email or subject line. Only use this if it is a really, really urgent or important message.

27. Avoid long sentences.
Try to keep your sentences to a maximum of 15-20 words. Email is meant to be a quick medium and requires a different kind of writing than letters. Also take care not to send emails that are too long. If a person receives an email that looks like a dissertation, chances are that they will not even attempt to read it!

28. Don't send or forward emails containing libelous, defamatory, offensive, racist or obscene remarks.
By sending or even just forwarding one libelous, or offensive remark in an email, you and your company can face court cases resulting in multi-million dollar penalties.

29. Don't forward virus hoaxes and chain letters.

If you receive an email message warning you off a new unstoppable virus that will immediately delete everything from your computer, this is most probably a hoax. By forwarding hoaxes you use valuable bandwidth and sometimes virus hoaxes contain viruses themselves, by attaching a so-called file that will stop the dangerous virus. The same goes for chain letters that promise incredible riches or ask your help for a charitable cause. Even if the content seems to be bona fide, the senders are usually not. Since it is impossible to find out whether a chain letter is real or not, the best place for it is the recycle bin.

30. Keep your language gender neutral.
In this day and age, avoid using sexist language such as: 'The user should add a signature by configuring his email program'. Apart from using he/she, you can also use the neutral gender: ''The user should add a signature by configuring the email program'.


31. Don't reply to Spam.
By replying to Spam or by unsubscribing, you are confirming that your email address is 'live'. Confirming this will only generate even more Spam. Therefore, just hit the delete button or use email software to remove Spam automatically.

32. Use cc: field sparingly.
Try not to use the cc: field unless the recipient in the cc: field knows why they are receiving a copy of the message. Using the cc: field can be confusing since the recipients might not know who is supposed to act on the message. Also, when responding to a cc: message, should you include the other recipient in the cc: field as well? This will depend on the situation. In general, do not include the person in the cc: field unless you have a particular reason for wanting this person to see your response. Again, make sure that this person will know why they are receiving a copy.

How do you enforce email etiquette?
The first step is to create a written email policy. This email policy should include all the do's and don't concerning the use of the company's email system and should be distributed amongst all employees. Secondly, employees must be trained to fully understand the importance of email etiquette. Finally, implementation of the rules can be monitored by using email management software and email response tools.

Wednesday, November 26, 2008

Folder Delete without Session Expire in C#.NET

protected void Page_PreInit(Object sender, EventArgs e)
{
PropertyInfo p = typeof(System.Web.HttpRuntime).GetProperty("FileChangesMonitor", BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static);
object o = p.GetValue(null, null);
FieldInfo f = o.GetType().GetField("_dirMonSubdirs", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.IgnoreCase);
object monitor = f.GetValue(o);
MethodInfo m = monitor.GetType().GetMethod("StopMonitoring", BindingFlags.Instance | BindingFlags.NonPublic);
m.Invoke(monitor, new object[] { });
}
Use System.Reflection

Saturday, November 15, 2008

Manase Relax Pls

http://www10.asphost4free.com/ursenix/Manasey_Relax_Pls.pdf

Game Links

http://www.janbrett.com/piggybacks/mouse_concentration.htm

http://www.mindexercisepuzzles.com/start.php

Javascript Code to display Time

script language="javascript" type="text/javascript">
function startTime()
{
var AmPm;
var today=new Date();
var h=today.getHours();
var m=today.getMinutes();
var s=today.getSeconds();

// add a zero in front of numbers<10
AmPm=checkAmPm(h);
h=check12hrs(h);
m=checkTime(m);
s=checkTime(s);

document.getElementById('<%=lblTime.ClientID %>').innerHTML=h+":"+m+":"+s +""+AmPm;
t=setTimeout('startTime()',500);
}

function checkTime(i)
{
if (i<10)
{
i="0" + i;
}
return i;
}
// Check for 12 hrs
function check12hrs(hr)
{
if (hr>12)
{
hr=hr - 12;
}
return hr;
}

function checkAmPm(hr)
{
if (hr>12)
{
AmPm="PM"
}
else
{
AmPm="AM";
}
return AmPm;
}
// End Script

Chennai Suburban Rail Map

Thursday, November 13, 2008

How to Resize an Image?

Fit the Pic Script// Title
script language="Javascript"
var arrTemp=self.location.href.split("?");
var picUrl = (arrTemp.length>0)?arrTemp[1]:"";
var NS = (navigator.appName=="Netscape")?true:false;

function FitPic() {
iWidth = (NS)?window.innerWidth:document.body.clientWidth;
iHeight = (NS)?window.innerHeight:document.body.clientHeight;
iWidth = document.images[0].width - iWidth;
iHeight = document.images[0].height - iHeight;
window.resizeBy(iWidth, iHeight);
self.focus();
};
//script end
BODY bgcolor="#000000" onload='FitPic();' topmargin="0"
marginheight="0" leftmargin="0" marginwidth="0">
document.write( "" );

Thursday, October 9, 2008

How to disable Right Click using Javascript?

Just add the below script in ur page..

var isnn,isie

if(navigator.appName=='Microsoft Internet Explorer') //check the browser
{ isie=true }

if(navigator.appName=='Netscape')
{ isnn=true }
function key(k)
{
if(isie) {
if(event.keyCode==17 || event.keyCode==18 || event.keyCode==93) {
alert("Sorry, you do not have permission to press this key.")
return false;
}
}

if(isnn){
alert("Sorry, you do not have permission to press this key.")
return false; }
}
document.oncontextmenu = function(){return false}
if(document.layers) {
window.captureEvents(Event.MOUSEDOWN);
window.onmousedown = function(e){
if(e.target==document)return false;
}
}
else {
document.onmousedown = function(){return false}
document.onkeydown=key;
}

Coding Standards

1.Naming Conventions and Standards

Note :
The terms Pascal Casing and Camel Casing are used throughout this document.
Pascal Casing - First character of all words are Upper Case and other characters are lower case.
Example: BackColor
Camel Casing - First character of all words, except the first word are Upper Case and other characters are lower case.
Example: backColor

1.Use Pascal casing for Class names

public class HelloWorld
{
...
}

2.Use Pascal casing for Method names

void SayHello(string name)
{
...
}


3.Use Camel casing for variables and method parameters

int totalCount = 0;
void SayHello(string name)
{
string fullMessage = "Hello " + name;
...
}

4.Use the prefix “I” with Camel Casing for interfaces ( Example: IEntity )

5.Do not use Hungarian notation to name variables.

In earlier days most of the programmers liked it - having the data type as a prefix for the variable name and using m_ as prefix for member variables. Eg:

string m_sName;
int nAge;

However, in .NET coding standards, this is not recommended. Usage of data type and m_ to represent member variables should not be used. All variables should use camel casing.

Some programmers still prefer to use the prefix m_ to represent member variables, since there is no other easy way to identify a member variable.


6.Use Meaningful, descriptive words to name variables. Do not use abbreviations.

Good:

string address
int salary

Not Good:

string nam
string addr
int sal

7.Do not use single character variable names like i, n, s etc. Use names like index, temp

One exception in this case would be variables used for iterations in loops:

for ( int i = 0; i < count; i++ )
{
...
}

If the variable is used only as a counter for iteration and is not used anywhere else in the loop, many people still like to use a single char variable (i) instead of inventing a different suitable name.

8.Do not use underscores (_) for local variable names.

9.All member variables must be prefixed with underscore (_) so that they can be identified from other local variables.

10.Do not use variable names that resemble keywords.

11.Prefix boolean variables, properties and methods with “is” or similar prefixes.

Ex: private bool _isFinished

12.Namespace names should follow the standard pattern

...

13.Use appropriate prefix for the UI elements so that you can identify them from the rest of the variables.

There are 2 different approaches recommended here.

a.Use a common prefix ( ui_ ) for all UI elements. This will help you group all of the UI elements together and easy to access all of them from the intellisense.

b.Use appropriate prefix for each of the ui element. A brief list is given below. Since .NET has given several controls, you may have to arrive at a complete list of standard prefixes for each of the controls (including third party controls) you are using.


Control
Prefix
Label
lbl
TextBox
txt
DataGrid
dtg
Button
btn
ImageButton
imb
Hyperlink
hlk
DropDownList
ddl
ListBox
lst
DataList
dtl
Repeater
rep
Checkbox
chk
CheckBoxList
cbl
RadioButton
rdo
RadioButtonList
rbl
Image
img
Panel
pnl
PlaceHolder
phd
Table
tbl
Validators
val



14.File name should match with class name.

For example, for the class HelloWorld, the file name should be helloworld.cs (or, helloworld.vb)

15.Use Pascal Case for file names.



2.Indentation and Spacing

1.Use TAB for indentation. Do not use SPACES. Define the Tab size as 4.

2.Comments should be in the same level as the code (use the same level of indentation).

Good:

// Format a message and display

string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );

Not Good:

// Format a message and display
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );

3.Curly braces ( {} ) should be in the same level as the code outside the braces.


4.Use one blank line to separate logical groups of code.

Good:
bool SayHello ( string name )
{
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;

string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

MessageBox.Show ( message );

if ( ... )
{
// Do something
// ...

return false;
}

return true;
}

Not Good:

bool SayHello (string name)
{
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );
if ( ... )
{
// Do something
// ...
return false;
}
return true;
}

5.There should be one and only one single blank line between each method inside the class.

6.The curly braces should be on a separate line and not in the same line as if, for etc.

Good:
if ( ... )
{
// Do something
}

Not Good:

if ( ... ) {
// Do something
}

7.Use a single space before and after each operator and brackets.

Good:
if ( showResult == true )
{
for ( int i = 0; i < 10; i++ )
{
//
}
}

Not Good:

if(showResult==true)
{
for(int i= 0;i<10;i++)
{
//
}
}


8.Use #region to group related pieces of code together. If you use proper grouping using #region, the page should like this when all definitions are collapsed.



9.Keep private member variables, properties and methods in the top of the file and public members in the bottom.

3.Good Programming practices

1.Avoid writing very long methods. A method should typically have 1~25 lines of code. If a method has more than 25 lines of code, you must consider re factoring into separate methods.

2.Method name should tell what it does. Do not use mis-leading names. If the method name is obvious, there is no need of documentation explaining what the method does.

Good:
void SavePhoneNumber ( string phoneNumber )
{
// Save the phone number.
}

Not Good:

// This method will save the phone number.
void SaveDetails ( string phoneNumber )
{
// Save the phone number.
}

3.A method should do only 'one job'. Do not combine more than one job in a single method, even if those jobs are very small.

Good:
// Save the address.
SaveAddress ( address );

// Send an email to the supervisor to inform that the address is updated.
SendEmail ( address, email );

void SaveAddress ( string address )
{
// Save the address.
// ...
}

void SendEmail ( string address, string email )
{
// Send an email to inform the supervisor that the address is changed.
// ...
}

Not Good:

// Save address and send an email to the supervisor to inform that
// the address is updated.
SaveAddress ( address, email );

void SaveAddress ( string address, string email )
{
// Job 1.
// Save the address.
// ...

// Job 2.
// Send an email to inform the supervisor that the address is changed.
// ...
}

4.Use the c# or VB.NET specific types (aliases), rather than the types defined in System namespace.

int age; (not Int16)
string name; (not String)
object contactInfo; (not Object)


Some developers prefer to use types in Common Type System than language specific aliases.

5.Always watch for unexpected values. For example, if you are using a parameter with 2 possible values, never assume that if one is not matching then the only possibility is the other value.

Good:

If ( memberType == eMemberTypes.Registered )
{
// Registered user… do something…
}
else if ( memberType == eMemberTypes.Guest )
{
// Guest user... do something…
}
else
{
// Un expected user type. Throw an exception
throw new Exception (“Un expected value “ + memberType.ToString() + “’.”)

// If we introduce a new user type in future, we can easily find
// the problem here.
}

Not Good:

If ( memberType == eMemberTypes.Registered )
{
// Registered user… do something…
}
else
{
// Guest user... do something…

// If we introduce another user type in future, this code will
// fail and will not be noticed.
}

6.Do not hardcode numbers. Use constants instead. Declare constant in the top of the file and use it in your code.

However, using constants are also not recommended. You should use the constants in the config file or database so that you can change it later. Declare them as constants only if you are sure this value will never need to be changed.

7.Do not hardcode strings. Use resource files.

8.Convert strings to lowercase or upper case before comparing. This will ensure the string will match even if the string being compared has a different case.

if ( name.ToLower() == “john” )
{
//…
}

9.Use String.Empty instead of “”

Good:

If ( name == String.Empty )
{
// do something
}

Not Good:

If ( name == “” )
{
// do something
}


10.Avoid using member variables. Declare local variables wherever necessary and pass it to other methods instead of sharing a member variable between methods. If you share a member variable between methods, it will be difficult to track which method changed the value and when.

11.Use enum wherever required. Do not use numbers or strings to indicate discrete values.

Good:
enum MailType
{
Html,
PlainText,
Attachment
}

void SendMail (string message, MailType mailType)
{
switch ( mailType )
{
case MailType.Html:
// Do something
break;
case MailType.PlainText:
// Do something
break;
case MailType.Attachment:
// Do something
break;
default:
// Do something
break;
}
}


Not Good:

void SendMail (string message, string mailType)
{
switch ( mailType )
{
case "Html":
// Do something
break;
case "PlainText":
// Do something
break;
case "Attachment":
// Do something
break;
default:
// Do something
break;
}
}
12.Do not make the member variables public or protected. Keep them private and expose public/protected Properties.

13.The event handler should not contain the code to perform the required action. Rather call another method from the event handler.

14.Do not programmatically click a button to execute the same action you have written in the button click event. Rather, call the same method which is called by the button click event handler.

15.Never hardcode a path or drive name in code. Get the application path programmatically and use relative path.

16.Never assume that your code will run from drive "C:". You may never know, some users may run it from network or from a "Z:".

17.In the application start up, do some kind of "self check" and ensure all required files and dependancies are available in the expected locations. Check for database connection in start up, if required. Give a friendly message to the user in case of any problems.

18.If the required configuration file is not found, application should be able to create one with default values.

19.If a wrong value found in the configuration file, application should throw an error or give a message and also should tell the user what are the correct values.

20.Error messages should help the user to solve the problem. Never give error messages like "Error in Application", "There is an error" etc. Instead give specific messages like "Failed to update database. Please make sure the login id and password are correct."

21.When displaying error messages, in addition to telling what is wrong, the message should also tell what should the user do to solve the problem. Instead of message like "Failed to update database.", suggest what should the user do: "Failed to update database. Please make sure the login id and password are correct."

22.Show short and friendly message to the user. But log the actual error with all possible information. This will help a lot in diagnosing problems.

23.Do not have more than one class in a single file.

24.Have your own templates for each of the file types in Visual Studio. You can include your company name, copy right information etc in the template. You can view or edit the Visual Studio file templates in the folder C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\ItemTemplatesCache\CSharp\1033. (This folder has the templates for C#, but you can easily find the corresponding folders or any other language)

25.Avoid having very large files. If a single file has more than 1000 lines of code, it is a good candidate for refactoring. Split them logically into two or more classes.

26.Avoid public methods and properties, unless they really need to be accessed from outside the class. Use “internal” if they are accessed only within the same assembly.

27.Avoid passing too many parameters to a method. If you have more than 4~5 parameters, it is a good candidate to define a class or structure.

28.If you have a method returning a collection, return an empty collection instead of null, if you have no data to return. For example, if you have a method returning an ArrayList, always return a valid ArrayList. If you have no items to return, then return a valid ArrayList with 0 items. This will make it easy for the calling application to just check for the “count” rather than doing an additional check for “null”.

29.Use the AssemblyInfo file to fill information like version number, description, company name, copyright notice etc.

30.Logically organize all your files within appropriate folders. Use 2 level folder hierarchies. You can have up to 10 folders in the root folder and each folder can have up to 5 sub folders. If you have too many folders than cannot be accommodated with the above mentioned 2 level hierarchy, you may need re factoring into multiple assemblies.

16.Make sure you have a good logging class which can be configured to log errors, warning or traces. If you configure to log errors, it should only log errors. But if you configure to log traces, it should record all (errors, warnings and trace). Your log class should be written such a way that in future you can change it easily to log to Windows Event Log, SQL Server, or Email to administrator or to a File etc without any change in any other part of the application. Use the log class extensively throughout the code to record errors, warning and even trace messages that can help you trouble shoot a problem.

17.If you are opening database connections, sockets, file stream etc, always close them in the finally block. This will ensure that even if an exception occurs after opening the connection, it will be safely closed in the finally block.

18.Declare variables as close as possible to where it is first used. Use one variable declaration per line.

19.Use StringBuilder class instead of String when you have to manipulate string objects in a loop. The String object works in weird way in .NET. Each time you append a string, it is actually discarding the old string object and recreating a new object, which is a relatively expensive operations.

Consider the following example:

public string ComposeMessage (string[] lines)
{
string message = String.Empty;

for (int i = 0; i < lines.Length; i++)
{
message += lines [i];
}

return message;
}

In the above example, it may look like we are just appending to the string object ‘message’. But what is happening in reality is, the string object is discarded in each iteration and recreated and appending the line to it.

If your loop has several iterations, then it is a good idea to use StringBuilder class instead of String object.

See the example where the String object is replaced with StringBuilder.

public string ComposeMessage (string[] lines)
{
StringBuilder message = new StringBuilder();

for (int i = 0; i < lines.Length; i++)
{
message.Append( lines[i] );
}

return message.ToString();
}


4.Architecture

1.Always use multi layer (N-Tier) architecture.

2.Never access database from the UI pages. Always have a data layer class which performs all the database related tasks. This will help you support or migrate to another database back end easily.

3.Use try-catch in your data layer to catch all database exceptions. This exception handler should record all exceptions from the database. The details recorded should include the name of the command being executed, stored proc name, parameters, connection string used etc. After recording the exception, it could be re thrown so that another layer in the application can catch it and take appropriate action.

4.Separate your application into multiple assemblies. Group all independent utility classes into a separate class library. All your database related files can be in another class library.

5.ASP.NET

1.Do not use session variables throughout the code. Use session variables only within the classes and expose methods to access the value stored in the session variables. A class can access the session using System.Web.HttpCOntext.Current.Session

2.Do not store large objects in session. Storing large objects in session may consume lot of server memory depending on the number of users.

3.Always use style sheet to control the look and feel of the pages. Never specify font name and font size in any of the pages. Use appropriate style class. This will help you to change the UI of your application easily in future. Also, if you like to support customizing the UI for each customer, it is just a matter of developing another style sheet for them

6.Comments

Good and meaningful comments make code more maintainable. However,

1.Do not write comments for every line of code and every variable declared.

2.Use // or /// for comments. Avoid using /* … */

3.Write comments wherever required. But good readable code will require very less comments. If all variables and method names are meaningful, that would make the code very readable and will not need many comments.

4.Do not write comments if the code is easily understandable without comment. The drawback of having lot of comments is, if you change the code and forget to change the comment, it will lead to more confusion.

5.Fewer lines of comments will make the code more elegant. But if the code is not clean/readable and there are less comments, that is worse.

6.If you have to use some complex or weird logic for any reason, document it very well with sufficient comments.

7.If you initialize a numeric variable to a special number other than 0, -1 etc, document the reason for choosing that value.

8.The bottom line is, write clean, readable code such a way that it doesn't need any comments to understand.

9.Perform spelling check on comments and also make sure proper grammar and punctuation is used.

7.Exception Handling

1.Never do a 'catch exception and do nothing'. If you hide an exception, you will never know if the exception happened or not. Lot of developers uses this handy method to ignore non significant errors. You should always try to avoid exceptions by checking all the error conditions programmatically. In any case, catching an exception and doing nothing is not allowed. In the worst case, you should log the exception and proceed.

2.In case of exceptions, give a friendly message to the user, but log the actual error with all possible details about the error, including the time it occurred, method and class name etc.

3.Always catch only the specific exception, not generic exception.

Good:


void ReadFromFile ( string fileName )
{
try
{
// read from file.
}
catch (FileIOException ex)
{
// log error.
// re-throw exception depending on your case.
throw;
}
}

Not Good:


void ReadFromFile ( string fileName )
{
try
{
// read from file.
}
catch (Exception ex)
{
// Catching general exception is bad... we will never know whether
// it was a file error or some other error.
// Here you are hiding an exception.
// In this case no one will ever know that an exception happened.

return "";
}
}


4.No need to catch the general exception in all your methods. Leave it open and let the application crash. This will help you find most of the errors during development cycle. You can have an application level (thread level) error handler where you can handle all general exceptions. In case of an 'unexpected general error', this error handler should catch the exception and should log the error in addition to giving a friendly message to the user before closing the application, or allowing the user to 'ignore and proceed'.

5.When you re throw an exception, use the throw statement without specifying the original exception. This way, the original call stack is preserved.

Good:

catch
{
// do whatever you want to handle the exception

throw;
}

Not Good:

catch (Exception ex)
{
// do whatever you want to handle the exception

throw ex;
}

6.Do not write try-catch in all your methods. Use it only if there is a possibility that a specific exception may occur and it cannot be prevented by any other means. For example, if you want to insert a record if it does not already exists in database, you should try to select record using the key. Some developers try to insert a record without checking if it already exists. If an exception occurs, they will assume that the record already exists. This is strictly not allowed. You should always explicitly check for errors rather than waiting for exceptions to occur. On the other hand, you should always use exception handlers while you communicate with external systems like network, hardware devices etc. Such systems are subject to failure anytime and error checking is not usually reliable. In those cases, you should use exception handlers and try to recover from error.

7.Do not write very large try-catch blocks. If required, write separate try-catch for each task you perform and enclose only the specific piece of code inside the try-catch. This will help you find which piece of code generated the exception and you can give specific error message to the user.

8.Write your own custom exception classes if required in your application. Do not derive your custom exceptions from the base class SystemException. Instead, inherit from ApplicationException.

Sunday, July 20, 2008

Download Method

public void downloadmethod(string filename)
{
if (filename != "")
{

string path = Server.MapPath(@"Invoice\" + filename);

System.IO.FileInfo file = new System.IO.FileInfo(path);

if (file.Exists)
{
Response.Clear();

Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);

Response.AddHeader("Content-Length", file.Length.ToString());

Response.ContentType = "application/octet-stream";

Response.WriteFile(file.FullName);

Response.End();
}



}

}

Friday, June 27, 2008

Javascript Counter

function textCounter(field,cntfield,maxlimit)
{
if (field.value.length > maxlimit) // if too long...trim it!
field.value = field.value.substring(0, maxlimit);
else
cntfield.value = maxlimit - field.value.length;
}
function update()
{
var limit =10;
var message = document.getElementById('message2').value;
var old = document.getElementById('txtcounter2').value;
document.getElementById('txtcounter2').value=message.length;
if(document.getElementById('txtcounter2').value > limit && old <= limit)
{
alert('Too much data in the text box!');
if(document.styleSheets)
{
document.getElementById('txtcounter2').style.fontWeight = 'bold';
document.getElementById('txtcounter2').style.color = '#ff0000';
}
}
else if(document.getElementById('txtcounter2').value <= limit && old > limit && document.styleSheets )
{
document.getElementById('txtcounter2').style.fontWeight = 'normal';
document.getElementById('txtcounter2').style.color = '#000000';
}
}
onkeyup="textCounter(this,txtcount1,125)">
onkeyup=update();