Window falls down

The window on my drivers side door falls down like a quarter of an inch when I shut the door.

How would I go about tightening things up in there so that it doesnt do that?

I have an extra drives side door with the glass and everything in it and it seems to feel tighter but Im not entirely sure since its not on a van for me to observe when closed. Would it be easier just to use the window regulator and stuff from that door in the good door on the van?

Your regulator might have some worn out teeth. Add some weld and file the teeth back into shape or replace with a better regulator. Maybe it's just the spring on your regulator that is weak. I've seen this situation many times. You are not alone. Good luck!