[GFreemen]

а если так

var zz1:Object={};
zz={};
zz.qwe=function(){
	kill(this);
}
function kill (asd) {
	for(var i in this){
		if(this[i]===asd){
			delete this[i];
			trace(i+"   "+this[i]);//zz   undefined
		}
	}
}
zz.qwe();
trace("end "+zz);//end undefined
trace("end1 "+zz1);//end1 [object Object]