How to call two functions with one button?

1

Im doing something wrong.

I have written two arrays for two separate functions and trying to have a button call both. How is this done properly? The function calls, collection() and left() are conflicting.
Currently left() isnt working, but with collection() commented out it does.
(AS2).

collection_btn.onPress = function(){
_root.introscroller.gotoAndStop(1);
collection_btn.gotoAndStop(2);
collection_btn.enabled = false;
collection();
left();
}