Question

I am using asp.net 2.0. I have 5 web pages in my project. I want to calculate the
length of time for which visitor view the page.

Answer 1

Outline for a tracking system:

1. Server-side: When the visitor requests the page, generate a unique id and include it in the page. Save the unique id with the user, page, and any other information you wish to track.
2. Client-side using javascript: When window.onunload fires, send an ajax call to the server to say the user has finished with the page identified by the unique id. Looking up the id saved in step 1, update the length of time visited.

Alternatively, use something like Google Analytics, which does a stellar job of tracking visitors.