I hooked my Mac Mini up to my HDTV plasma display and eerythiing worked. However, when I went into System Prefrences, I saw my resolution was only 800x600. Me, being the person I am, changed it to 1024x768, and now theres no display. I reset the computer and still, nothing. How do i revert back to my default resolution if I cant see what I'm doing? Please help.