93 Camry radio stuck in "HELP" mode

I have a 1993 toyota camry that I recently changed the battery on and afterwards the antitheft radio would not work. I recently bought this car and did not know where to find the original owners code to unlock the radio until AFTER I locked the radio up, meaning that it's now stuck with a "HELP" message across the screen. I do have the code now, I just don;t know how to get it out of this help screen. Any help would be appreciated.