Need someone to "FIX" script in shopping cart that is not adding products

I will try this again, but i'm looking for someone to "FIX" an existing shopping cart where I am able to add categories, but when trying to add products under the category, nothing happens. I had someone do the analysis, but pretty much heard what I had described, so I am in need of a fix. the functionalities of the shopping cart are all in place other than this script to add products. thanks and look forward to working with someone to correct this problem for me. my client has become impatient and we need it soon.