Biggy

Hey, during our last team practice i noticed my front grip frame screw was gone, now im at college and have no tools and I can not take the gun in the building into my room, or i could loose my housing. So there is no way for me to just take off the grip frame and run to the hardware store because i cant leave the gun in my room for fear the roommate will mess with it or the ra will see it. So to make a long story short, what is the damn thread and size of the grip frame screw so i can go buy one?