VW Golf Mk4 1998 Driver Door sometimes not shutting?

Hi, I have just purchased a VW Golf with a few problems, hopefully just small ones.
The first one is when i bought the car the interior front passenger door handle had a piece of string held round the passenger head rest. When i untied it i found that the passenger door didn't stay shut on its own. I played around with the switches on the drivers side door and slammed it a few times and it worked. Great! Then i took someone to work in it, now it doesn't work again. My other problem is the back passenger door drivers side doesnt open at all inside or outside! I am going to try the coat hanger thing at the weekend.