He does use it: In the level_load instruction.

@Zxya:
Actions are a special form of functions.
Unlike functions actions do not take any parameters and thus don't need the brackets behind the action name.
Have you tried this version:
Code:

---

 
STRING test = "test.wmb";

function main(){
	level_load(test);
	wait(2);
	
	while(1){
		wait(1);
	}
}

action i_am_rotating
{	
	while(me!=NULL){
		my.pan+=3;
	        wait(1);
	}
}

---