58771 Fix my OSCommerce Script

Take a look at [login to view URL] When I add a product to my shopping cart, it gets added. However, when I click on the Cart button on the top right to load the shopping cart, it shows that the cart is empty! I tried adding 1 item, then going back to the catalog to add another item, but everytime the cart only shows the latest item I added. Looking for somebody to fix it.