Is there a key or keys that command the back button to go to the previous page?

   If you have a special Internet keyboard, there should be a special single key for that.
   For regular keyboards, your browser should have a special key combination to cause it to go Back.  If you put your cursor over the Back button or find Back in the menu, it should tell you what that key combination is.  I just checked my browsers (IE7, Netscape, and FireFox) and they all show Alt - Left to be the combination.  So if you press the Alt button and the left arrow button (this is to the right of your regular keys and has four keys, each with a different arrow on it (up, down, left, and right) at the same time, it should go back.
   Additional Tip - in IE7 if you press the Alt button by itself, it will reveal the classic menus.

thanks,     question answered.