Professional :: Make A Button Active If Another Button Is Clicked?

I want to make a button (or graphic) active and visible if another button is clicked. But it must be invisible and unclickable before the other button is clicked. (this is a "find the differences between the 2 pictures game" and I want circles to appear over the differences that the user finds but only after he clicks it)

The button (or graphic) I want to become active has instance name of "sockcircle_btn" The button you click to make it appear is called "sock_btn"

In the first frame of the sockcircle_btn layer, this is my code

sockcircle_btn.addEventListener(MouseEvent.CLICK,sockcircledisable);
function sockcircledisable(evt:MouseEvent):void{
sockcircle_btn.mouseEnabled = false;
}
 
In the sock_btn frame (frame 3) this is my code

sock_btn.addEventListener(MouseEvent.CLICK,sockcircleenable);
function sockcircleenable(evt:MouseEvent):void{
sockcircle_btn.mouseEnabled = true;
}

The file is setup to loop between frames 2-3. But the sockcircle_btn never enables even when sock_btn is clicked.