Checking the parent page address in child page using .NET

I am using C# language.

I am facing one problem, please see the details below:

I h开发者_开发知识库ave a parent page with address (http://www.espireinfo.com/coursefinder/findaprice.aspx?SchoolCode=LOL&ProgCode=ENGBUS&School=London%20Leicester%20square&Programme=English%20for%20Business)

which have a button, which on click put some values in session and after putting some value in session it redirect page to this page (http://www.espireinfo.com/coursefinder/BookNow.aspx), now in this page I want to check

if requested parent page == "findaprice.aspx" then
{
    do something!
}

Please suggest! how to should achieve above code logic using C# language.

Thanks!

See HttpWebRequest.Referer property.