need help adjusting action

My cheap mockingbird with the all in one bridge/tailpiece needs help. I just took all the strings off to clean the fretboard, and nobody told me that the whole tailpiece was going to fall off when I did this. The neck is adjusted fine, but now I can't get my action set the way I had it before. My question is, what do the two screws on the back of the tailpiece do? I know that the two large screws adjust the string height, but I can't get it quite right. You might search for a picture of the bronze Bc rich's to see what this tailpice looks like.

From what I can remember..... the two screws on the tail piece are for adjusting the closness of the tail piece to the large screws they hook around, parhaps to hone the intonation..