2005 Dodge Caravan Passenger window loose

The front passenger window is loose in the door. When you lower the window it's fine. When you try to close it, the window goes up a little crooked and stops approx. 1/4" from the top. When you let it back down a little, it CLUNKS, then goes back up the rest of the way fine. I took the door panel off to look inside and the only thing I noticed is that if you open both front windows half way and try to lift the glass with your fingers, the driver side is tight and the passenger side is loose and can be lifted up easly. I didn't want to take the diver side door apart to compare and without doing that I can't figure out what holds the class in place so it won't shift when closing the window. Any help would be appreciated.