Every time my web application hits SQL server a query or Procedure should be called and should return its values to web application.

How can i do this?

Using delegates and events.

I want to include auto log off functionality in my application. When a member logs in with different session the previous session should expire automatically.

I am doing this with a timer control. Every interval it checks for member log from database.

I want to reduce database hits. I want to check member log only when member does some activity on application.

1. You could have a collumn which stores SessionID. When user logs in from another location, it replaces the SessionID and he is logged off from old location.
2. If I was doing that with timer in ASP.NET application, application would got crazy.
3. On each user action you can call function to check if user is logged.

Exactly,

that you said i can do with the help of delegates and events. Can you help me more in creating delegate?

I use them rarely, but some good books/tutorials could be found on Internet. I recommend you Microsoft Visual C# 2008 - John Sharp - Microsoft Press.

I have more then 50 pages in my application. I want something common to entire application. wch will check On each user action for member log in database.

OR

Any other way to achieve "auto log off functionality"??

- Make that procedure into Global.asax file.
- I think it's stupid that 2 same users are logged in the same time.