How to program ford key fob? I have a 1999 Mercury Mountaineer?

First unlock doors once, turn key from off to run position 4 times ending in run the 4th time. this has to be done within 4 seconds or program will not work.. after the fourth time if done right locks should lock unlock once to let u know program is entered.. imediatly press the unlock butom on the fob control within 5 seconds.. if locks and horn beeps done.. remote is programed. in case a step was missed wait at least 1 minute and start again..