Animate HTML5 Canvas/Javascript, Math Help Please

Hello,

I'm converting my AS3 to JS.  My AS3 math code isn't working with JS, and despite around 10 hours spent so far, I cannot figure out what I'm doing wrong.  If anyone could kindly help, I would greatly appreciate it!

I am at my wits end!  I don't understand what I'm doing wrong.  Thank you for any help!

math_drag_as3.fla code (this works properly):

// VARIABLES
var selectedAircraft:Object;
var myAtan2:Number;
var radians:Number
var radiansAircraftCenter:Number;
var aircraftCenterPointX:Number = 50;
var aircraftCenterPointY:Number = 50;
var movementInProgress:Boolean = false;
var aircraftBuildInProgress:Boolean = false;

// TOWTARGET LISTENERS
towTarget.addEventListener(MouseEvent.MOUSE_DOWN, startMove);
towTarget.addEventListener(MouseEvent.MOUSE_UP, stopMove);

// --- Add parameters to aircraft object
selectedAircraft.aircraftHeight = 100;
selectedAircraft.aircraftWidth = 100;
		
// --- Position aircraft object
selectedAircraft.aircraftRotation = 0;
selectedAircraft.rotation = 0;
selectedAircraft.aircraftX = 50;
selectedAircraft.aircraftY = 50;
selectedAircraft.x = 50;
selectedAircraft.y = 50;


radians = selectedAircraft.rotation * (Math.PI / 180);
radiansAircraftCenter = (selectedAircraft.rotation-90) * (Math.PI / 180);
towTarget.x = selectedAircraft.x + ((selectedAircraft.aircraftWidth/2) * Math.cos(radians));
towTarget.y = selectedAircraft.y + ((selectedAircraft.aircraftWidth/2) * Math.sin(radians));
aircraftCenterPointX = towTarget.x - ((selectedAircraft.aircraftHeight/2) * Math.cos(radiansAircraftCenter));
aircraftCenterPointY = towTarget.y - ((selectedAircraft.aircraftHeight/2) * Math.sin(radiansAircraftCenter));


	
function selected(e:MouseEvent):void {
	radians = selectedAircraft.rotation * (Math.PI / 180);
	radiansAircraftCenter = (selectedAircraft.rotation-90) * (Math.PI / 180);
	towTarget.x = selectedAircraft.x + ((selectedAircraft.aircraftWidth/2) * Math.cos(radians));
	towTarget.y = selectedAircraft.y + ((selectedAircraft.aircraftWidth/2) * Math.sin(radians));
	aircraftCenterPointX = towTarget.x - ((selectedAircraft.aircraftHeight/2) * Math.cos(radiansAircraftCenter));
}


function startMove(evt:MouseEvent):void {
	movementInProgress = true;
	evt.target.startDrag();
	
	stage.addEventListener(Event.ENTER_FRAME, checkMouse);
}

function stopMove(e:MouseEvent):void {
	selectedAircraft.aircraftX = selectedAircraft.x;
	selectedAircraft.aircraftY = selectedAircraft.y;
	selectedAircraft.aircraftRotation = selectedAircraft.rotation;
	movementInProgress = false;
	stopDrag();
	
	removeEventListener(MouseEvent.MOUSE_MOVE, checkMouse);
}

function checkMouse(evt:Event ):void {
	if (movementInProgress == true) {
		myAtan2 = Math.atan2(towTarget.y - aircraftCenterPointY, towTarget.x - aircraftCenterPointX);
		selectedAircraft.rotation = (myAtan2 * 180 / Math.PI) + 90;

		radians = selectedAircraft.rotation * (Math.PI / 180);
		radiansAircraftCenter = (selectedAircraft.rotation-90) * (Math.PI / 180);
		selectedAircraft.x = towTarget.x - ((selectedAircraft.aircraftWidth/2) * Math.cos(radians));
		selectedAircraft.y = towTarget.y - ((selectedAircraft.aircraftWidth/2) * Math.sin(radians));
		aircraftCenterPointX = towTarget.x - ((selectedAircraft.aircraftHeight/2) * Math.cos(radiansAircraftCenter));
		aircraftCenterPointY = towTarget.y - ((selectedAircraft.aircraftHeight/2) * Math.sin(radiansAircraftCenter));
	}
}

math_drag_js.fla (this doesn't work properly):

// VARIABLES
var myAtan2;
var radians;
var radiansAircraftCenter;
var aircraftCenterPointX = 50;
var aircraftCenterPointY = 50;

var towTarget = this.towTargetObj;
var selectedAircraft = this.selectedAircraftObj;

selectedAircraft.aircraftWidth = 100;
selectedAircraft.aircraftHeight = 100;

// TOWTARGET LISTENERS
towTarget.on("pressmove", function(evt){
	this.x = evt.stageX;
	this.y = evt.stageY;

	myAtan2 = Math.atan2(this.y - aircraftCenterPointY, this.x - aircraftCenterPointX);;
	selectedAircraft.rotation = (myAtan2 * 180 / Math.PI) + 0;

	radians = selectedAircraft.rotation * (Math.PI / 180);
	radiansAircraftCenter = (selectedAircraft.rotation - 0) * (Math.PI / 180);
	selectedAircraft.x = this.x - ((selectedAircraft.aircraftWidth/2) * Math.cos(radians));
	selectedAircraft.y = this.y - ((selectedAircraft.aircraftWidth/2) * Math.sin(radians));
	aircraftCenterPointX = this.x - ((selectedAircraft.aircraftHeight/2) * Math.cos(radiansAircraftCenter));
	aircraftCenterPointY = this.y - ((selectedAircraft.aircraftHeight/2) * Math.sin(radiansAircraftCenter));
	
	stage.update();
});