Can you just clarify what you mean by this? Do you mean if they click a link as the page is still loading? That's what it sounds like you mean, but that doesn't make a great deal of sense to me. Also is that URL actually in the address bar, or is it created by a htaccess redirect?
Sorry I dont think I explained it very well,
When the user first lands on the page the URI is /products.php?ptid=5 if the user then clicks on a product the URI changes to /products.php?ptid=5&pid=7. My issue is that while the user is at /products.php?ptid=5 my conditional statement checking that the URI matches /products.php?ptid=5 returns true if however the URI is /products.php?ptid=5&pid=7 it fails I need to be able to somehow use the /products.php?ptid=5 from /products.php?ptid=5&pid=7 so that my check returns true whatever happens as long as some of the URI is products.php?ptid=5 hope that makes more sense.