Javascript History Functionality in ASP

I'm trying to figure out a way to get the url of the page before the referr page. I know this is possible in Javascript using the History function... is there a way for me to do anything similar to this in ASP?

Basically I am trying to get the referr of an html page. I call an asp script through an image, which gives me the html page as a referrer so I need to go back one further.

Any ideas? Thanks!