central locking problem?

hi
i have a ford focus 1999.
the problem is the drivers door and the two back doors will not open from the inside or out. when i press the key fob nothing, no sound.
so i try to unlock by inserting the key, nothing, it will not open. the only way in is putting the key in the passengers door. so i get into the car, climb over to the driver side, and try to open the door, and it will not open.
please help me
chris