Simple question, just confirmation needed

Ok, am converting my program just in case register globals = off and just need someone "in the know" to tell me if I am on the right track or I got this concept all bungled in by poor tired overworked brain. If i take variables just as they come and *dont* use: $product_id=$_GET[product_id]; it wont work if globals are off. but if i use : $product_id=$_GET[product_id]; it WILL work if globals are on OR off or whatever.....right? If anybody has any other useful suggestions/warnings etc I should be aware of so that my code will run without a problem please tell me, even if its days after I originally posted this. Cheers, -Ryan