How to toggle between widescreen and Fullscreen in XBMC?

[BigSteel]

I played a widescreen verison of "Once Upon a Time in Mexico" on XBMC. It shows as full screen which messes up the AR. The file is an xvid .avi with AC3 sound. In XBMP there is a way to change this by enabling a couple of changes (can't remember what they are called at the moment). Is there a way to do this in XBMC as well?

[smokafatty]

Press the start button to switch from normal, zoom, and stretch.

Just change it to normal and it should go back to widescreen.