Thanks for you response Anthony... I'm sure I've already tried using the front sub-command dial and still nothing but I will try it again. But even if that was the case, the built-in flash does not pop up when I press the flash (lightning bolt) button when I'm in A,P,S or M mode. That's why I think the button may have a defect and not working..
Is there a way to find out if the previous owner set any custom functions that may still be programmed into the camera?