Millisecond Forums

I have a study in which I present five images to participants in random order but in five specified locations on the screen (top left, top right, center, bot left, bot right). Participants choose one image, and I would like that image to appear later in the study.  However, I keep running into "file not found" errors.  I did this same kind of programming earlier in the script for text values and it worked just fine.  Here is the relevant script (decontextualized for greater clarity and shortened by removing redundant code).