I have a classifieds website. In every classified, there is a back link which simply takes the browser back one step. This is because when users search classifieds, and click on one to view it, they can easily go back with a link also (instead of only the browser back button).

Here is the problem, if the classified is entered directly into the adress bar of a browser, or if somebody bookmarked a classified, then this back-link would take them someplace else...

Is there any way of making sure that the previous page is a certain page (index.php in my case)? This way I would only display the back link if the previous page was index.php...

Thanks