The door to the office in my condo keeps getting stuck when I try to close it fully. I looked at it today and saw that the problem is that it's sitting on the hinges crooked: the top is further into the opening than the bottom. So obviously at the other side the top is getting caught on the door frame when I try to close the door. How do I fix this so that the door is sitting on the hinges evenly, i.e. so it's perpendicular to the floor like it should be? Thanks for your help.