If your car was built after march 1, 1998 you will need 2 operating keys to program another key (These cars have the PATS II system). If the car was built before March 1, 1998 you have the PATS I system which lets you program a new key from just 1 operation key. I know this because I just went through the same thing. Follow the key programing procedure in your owners manual exactly. It is possible that Ford did not update the owners manual for cars built after March 1, 1998. There was no owners manual in the used 1998 Mystique that I bought. Good luck!
