How can I build a search engine using c sharp?

I am using visual studio 2008. I made a website based on .net platform. The whole site includes .aspx files. Now, I want to make a search option for the user. When a user want to find something from my site and press the search button; it should search for that input from the content of my site. And show the search results in a div.

I need the c# coding to build this service in my site.
 
Hope this is enough.