Movieblogpress gateway help - noob

i'm setting up the gateway/locker that's installed with movieblogpress but when the link to the offer is clicked, it shows up but it's cut off - too big for the gateway frame. the boxes that the user has to fill out to complete the offer are cut out of the screen so it can't be filled out.

is this due to the size of the window of the offer or is there some way i can change the size of the gateway background? something else i'm doing wrong?

sorry for the noob question. i'm new to content lockers and struggling a bit. haven't been able to find the solution anywhere in the forums and have yet to hear back from movieblogpress support.