Level Design Making a door on an ammo shop.

[Gauntlet]

I've been trying to make an object like a door close or a boulder roll across the doorway of the shop when the time limit is up. Does anyone know how to do this?
Also, when the second wave of my zombies spawn (just as the countdown timer hits 0) it freezes the whole game. Any ideas?

 

[Yoshilast]

Wow really? Look at the tutorial in the manual.

 

[Gauntlet]

Wow! Next time I'll use my eyes! Thanks!