Alter Quick Cart

We had another freelancer program a weight calculation script into quik cart. If the total weight equal x then it looks for that weight in the carriours and charges the appropiate amount. The freelancer is now mia and of u enter anything under 1 pound like .25 pounds for the weight the cart does not recongize teh product, it will show up in the admin panel but not in the cart iteself. This is a asap project and we fell it should be completed in less then 24 hours