Help need about unloading main movie

[onurcan1977]

There are hundreds of threads on the web about unloading movie but none of them work. For example, the code below gives this error: TypeError: Error #2007:

var alert:Boolean=true;
if (loaderInfo.url!="someurl") {
	removeSwf();
}
var swfHolder:Loader = new Loader();
function loadSwf(target:String):void {
	addChild(swfHolder);
	swfHolder.load(new URLRequest(target));
}
function removeSwf():void {
	removeChild(swfHolder);
}