247610 Install Google Checkout Zencrt

Hi, I'm looking for someone to help me with installation of the google checkout module for zencart. I have installed it and it goes to google checkout with all the items and shipping options, but when you press confirm order the google checkout screen goes blank, I have ensured the call back url is set in my merchant account. When I go to the response handler page it prompts me of a username and password. This should be a fairly simple project and I would like the bids to reflect this please (don't bid higher than $20 as I'm a student). Any further questions please PM. Cheers