1999 Other Nissan Models central locking

hi, i have a 1999 nissan micra 1.3 gx, and it has a prob with the central locking. the drivers door is opened by the key fob, and istantly relocks itself and the other doors. sometimes the doors lock themselves when i am inside the vehicle. just recently, the drivers door does not lock on occasions, but the other doors lock. any feedback would be gladly appreciated. thankyou.