[LVL ED] New Question: How to create a door

[Cruzore]

you don't need string& when they aren't callback syntax functions.
Also, do it under the cavein_function, since you want it to happen at the same time, also, by your move there, you got a function with nothing to do.
delete everything from cavein_function on and paste this:
void cavein_function(string &in asParent, string &in asChild, int alState)
{
PlaySoundAtEntity("", "explosion_rock_large.snt", "cave_in_1", 0, false);
SetEntityActive("cave_in_1", true);
SetEntityActive("cave_in_2", true);
CreateParticleSystemAtEntity("ParticleSystem_1", "ps_break_cavein.ps", "cave_in_1", false);
}