I just bought a 95 prizm for my son.We changed the battery,and now the radio is code E9,I think its the theft deterent thing thats stopping it from working,how do I unlock it.I dont have the orig papers on it,so I dont have the code to unlock it.The dealer said its too old for him to get the code,,does anybody have any experiance on these things,if so,clue me in on what to do-----thanks,,Jack