EasyUi Tree找所有上级父节点

JavaScript代码块

	function getFathers() {		//找所有上级父节点
	var node = $('#tt2').tree('getSelected');	
	if($('#tt2').tree('getParent', node.target))
	 {
	var parent = $('#tt2').tree('getParent', node.target);
	var str='node:'+node.text+', AllParents: '+parent.text;		
	while(1)
	{
		parent = $('#tt2').tree('getParent', parent.target);
		if(parent)
	    {str+=', '+parent.text;}
		else break;
	}
	alert(str);
	}
    else{
	alert("node:"+node.text+",该节点就是父节点，没有上级节点！！");
 }
}
	f