Duplicate:
How do I find the referring url that brought a user to my site in ASP.NET?
See Also:
How can I find what search terms (if any) brought a user to my site?
How do I find the referring url that brought a user to my site in ASP.NET?
How can I find what search terms (if any) brought a user to my site?
Request.UrlReferrer
But this isn't guaranteed to be correct or even exist.
The referer URL should be in the HTTP headers on the request.
E.g. Uri MyUrl = Request.UrlReferrer
See: http://msdn.microsoft.com/en-us/library/system.web.httprequest.urlreferrer.aspx
Request.UrlReferrer
http://msdn.microsoft.com/en-us/library/system.web.httprequest.urlreferrer.aspx