Hi. I am currently on Chapter I on the Monsterhouse game, and I can't figure..

Question for Monster House

Hi. I am currently on Chapter I on the Monsterhouse game, and I can't figure out how to push/pull objects across the room. I am stuck on the part where I first come into a room, and there are three boxes in front of me, and then instructions come up telling me that I am able to push/pull objects across the room, but when I try to do so, it doesnt let me. Also, the instructions say that I have to use the " R" button, or either the " b" button, but I can't tell which. I know that this is a kind of dumb question, but I was hoping that someone could give me an answer to this question. Thanks, I really would appreciate it.