Price not changing when attribute is selected

[mikelucid]

I was trying to install an old version of an express checkout on my site www.stretchshapes.net and it ended up not working properly and messing up my shopping cart.

First, the product menu isnt loading, even when i chck the source and the correct code is there.

Also, if you view a product when you change the size it doesnt update the price like it used to.

Did a JS fiel get corrupted or disconnected? please any insight is a great help... im at a loss

Also, before i made changed i did a compelte system backup, but things still didnt go back to normal...