按钮显示动态树

var mytree = new dTree('mytree');$(function(){$("#btn").bind("click",function(event){     $.getJSON('tree.htm', function(data){        $.each(data.tree, function(index, value){            var id = value.cid;            var pid = value.parent;            var name = value.name;            mytree.add(id, pid, name);        });alert(mytree);$(".dtree").append(document.write("mytree"));    });});})