What to do if good Remote won't program

I have a tested, good remote FOB for my 97 Lesabre. I went through all the stuff to program it as discribed in this fourm. It doesn't seem to work. When I hold down the Lock and UnLosck for 30 seconds, the doors don't cycle through or do anything. I know the remote is the right one, matched it up with the Dealer #. Have a brand new battery. What could be wrong? How can I program it to work? Thank you, Chris.