Models Disapearing >:0

[Samio]

ok this has got to be the most anoying thing ever. OK im in 3ds max and i see my model, i wana rotate or move it so i could see it at another angle but as soon as i start to rotate it THE MODEL DISAPEARS!!! I got this problem before but i dont remember how i fixed it, random keyboard smashing i think. I wana know what the hell do i press to stop it from doing that so i can rip that key off of my **** keyboard and toss it into the ocean!!!