Call a function inside a movieclip

Hi, I have a simple problem. I have a lengthy function declared on the first frame of my game, I would like to use this as code for the enemies, therefore I must call it inside their enterFrame section.
This is how I am trying to call it now:

onClipEvent (enterFrame) {
monsterScript(0, 1, “left”, 5, 5, 1, 1);
}

And I get nothing. However, interestingly enough, I know it’s not a problem with the function itself, because if I target the call to the root layer (I.E. _root.monsterScript(0, 1, “left”, 5, 5, 1, 1)) the whole screen begins behaving the way the monster should.