Problem with remote control for my new Element...

Question

Just bought a floor model 32" tv from circuit city. Got it hooked up just fine. One problem though. I can't seem to be able to change input settings. For example I want to switch from watching tv to playing my PS3 via the side input. The up/down, side to side, and enter buttons do not work to do this. the rest of the remote seems to be functioning but there does not appear to be anyway to change inputs. Any help would be much appreciated. Thanks. Dave T.