Need Help puttimg my Car in Program Mode(KeyFob)
 

I searched for this car year and haven't found it brought up.2004 Mercury Grand Marquis GS(Dont know if it has Conveinence pkg)
i picked it up used it didn't have a keyfob,i so bought one and found out how to program the keyfob.Turm the key off to run 4Xs ending on Run once the Door locks cycle/Lock n unlock the car is in Program mode.But after ending on run after the 4th turn the locks dont cycle.I tried doing it 5Xs,8Xs and 10Xs.So my question is,I just assumed this car came with a keyfob.Is it possible it was an option the original owner didnt get?And if so is there a way to get the car programmed for a keyfob.Thanks
https://cimg4.ibsrv.net/gimg/www.mer...32c7ba1735.jpg