I can't removeEventListener

1

how i can remove “removeEventListener” clicked mc?
this is my code.

 
var loop=function()
var mytime:Timer=new Timer(1500)
mytime.addEventListener(TimerEvent.TIMER,newBall)
mytime.start()
function newBall(e:TimerEvent):void{
var ball:MovieClip=new MovieClip()
ball.graphics.beginFill(0xFF8800)
ball.graphics.drawCircle(50,150,30)
addChild(ball)
anim(ball)
}
function anim(cmc){
 cmc.addEventListener(Event.ENTER_FRAME,loop)
 function loop(e:Event):void{
 e.target.x+=2
 }}
addEventListener(MouseEvent.MOUSE_DOWN,mdown)
function mdown(e:MouseEvent):void{
 var cname= getChildByName(e.target.name)
 trace(cname.name)
 //removeChild(cname)
 cname.removeEventListener(Event.ENTER_FRAME,loop)//problem line
 }