Hi guy's

Just after a little help although I think I know the answer;

Just recently I have been unable to get into my car via the drivers door it locks fine just won't unluck when turning the key as if it's stuck..

So now I have to get in through the passanger side which doesn't bother me as such it's just I'm selling the car shorlty and I'm going to look a bit of a tool getting through the passanger side not a good starting point to sell a car!!!

I know this is common on the Escorts but without buying a new set of locks is there any way of solving this probelm I'm tried the old WD40 but no joy.

Many thanks in advance

Carla