createjs: implement keyboard input from external script

I'm building a createjs game in Animate.  On frame 0 I have (in part) the following...

var goLeft = false;
var goRight = false;
var KEYCODE_LEFT=37,KEYCODE_RIGHT=39

window.onkeyup = keyUpHandler;
window.onkeydown = keyDownHandler;

function keyDownHandler(e){
	if(!e){
		var e = window.event;
	}
	switch(e.keyCode){
		case KEYCODE_LEFT: goLeft = true;break;
		case KEYCODE_RIGHT: goRight = true; break;
		case KEYCODE_UP: stage.swapChildren(gate, boarder);
	}
}

function keyUpHandler(e){
	if(!e){
		var e = window.event;
	}
	switch(e.keyCode){
		case KEYCODE_LEFT: goLeft = false;break;
		case KEYCODE_RIGHT: goRight = false; break;
	}
}

createjs.Ticker.addEventListener("tick", loopclip);
function loopclip(){
    if(goLeft) // something happens;
    if(goRight)  // the opposite happens;
}

This works just fine.  My question is, how do I move this to an external "game" js file?  Thanks.