I am setting up a shopping cart for a customer and their credit card processor is Go Emerchant. I downloaded the module and installed in my credit cards. I entered in the Transaction ID and the Order Prefix and turned the module on.

When I go to check out I can go through the first two steps of checking out but as soon as it goes to confirm my order and run the card I get a blank page and the url says:
http://laestrellitastore.net/index.p..._expires_year=

I am not skilled with php so I have no idea what is going on and why it wont process the order. Some one please HELP!!