It worked! thanks for the help! There is a trick though. The first time I disconnected the battery, waited about 30 seconds, then reconnected the battery. I then turned on the car and the radio. After the "code" appeared and the 5 digit code was put in. The radio did not work. The "code" still appeared. The second time I disconnect the battery, waited 30 minutes, then I turned on the car and the radio (all this was done when the battery was disconnected). I then turned off the radio and car's ignition. After the battery was reconnected the ignition and radio were turned on. After the "code" appeared the 5 digit code was added. It worked!
I believe the radio stores some memory when it is off after the battery was disconnected. To clear this the radio needed to be turned ON with the battery disconnected. (just a guess) Anyway, it is working now.