I have a gap between the top of my exterior door and the frame of about a half inch on the latch side. On the hinge side there is no gap. How do I straighten up the door to correct this problem? The top part of the door rubs on the frame when I shut the door espicially in humid weather.I have looked at the door to see if I can put a shim behind the bottom hinge but there is no gap at the bottom of the door on the latch side that would allow me to do this. This is a 60 year old house and the old interior door also have this problem. Any help or suggestions would be greatly appreciated.