Action script 3 question: addChild and removeChild on same button?

I’m trying to make a button that when u click once, the movieclip will be removed and second time back on stage and so forth…

somehow i get this error

ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
at flash.display:DisplayObjectContainer/removeChild()
at sample_fla::MainTimeline/btnClick()

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Anyone can help me with this, since I’m doing an interactive web for client and the deadline is near… thanks in advance.

these are my code:

///////////////////////////////////////////////////

stop();

var swf:MovieClip;
var loader:Loader= new Loader();
var defaultswf:URLRequest= new URLRequest("./newSwfImport.swf");
//default swf when loaded

loader.load(defaultswf);

//add to stage
allSwfLoadHere.addChild(loader);
var boolean:Boolean = true ;

function btnClick(event:MouseEvent):void {

if(boolean == true){
allSwfLoadHere.removeChild(loader);
boolean == false
}

if(boolean ==false){
allSwfLoadHere.addChild(loader);
boolean == true
}
}

newSwfImport.addEventListener(MouseEvent.CLICK,btnClick);

//////////////////////////////////////////////////////