title: Uncaught TypeError: Cannot read property 'init' of undefined on zTree_v3 library
body: <p>I got problem with using zTree library. this is my code</p>
  
  <pre><code>&lt;script type="text/javascript" src="&lt;?php echo base_url()?&gt;asset/js/jquery-1.4.4.min.js"&gt;&lt;/script&gt;
  &lt;script type="text/javascript" src="&lt;?php echo base_url()?&gt;asset/js/jquery.ztree.core-3.5.js"&gt;&lt;/script&gt;
  &lt;SCRIPT type="text/javascript"&gt;
      &lt;!--
      var setting = {
          data: {
              simpleData: {
                  enable: true
              }
          }
      };
  
      var zNodes =[
          { id:1, pId:0, name:"Custom Icon 01", open:true, iconOpen:"&lt;?php echo base_url()?&gt;asset/img/diy/1_open.png", iconClose:"&lt;?php echo base_url()?&gt;asset/img/diy/1_close.png"},
          { id:11, pId:1, name:"leaf node 01", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/2.png"},
          { id:12, pId:1, name:"leaf node 02", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/2.png"},
          { id:13, pId:1, name:"leaf node 03", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/2.png"},
          { id:2, pId:0, name:"Custom Icon 02", open:true, iconOpen:"&lt;?php echo base_url()?&gt;asset/img/diy/1_open.png", iconClose:"&lt;?php echo base_url()?&gt;asset/img/diy/1_close.png"},
          { id:21, pId:2, name:"leaf node 01", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/8.png"},
          { id:22, pId:2, name:"leaf node 02", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/8.png"},
          { id:23, pId:2, name:"leaf node 03", icon:"&lt;?php echo base_url()?&gt;asset/img/diy/8.png"}
  
      ];
  
      $(document).ready(function(){
          $.fn.zTree.init($("#treeDemo"), setting, zNodes);
      });
      //--&gt;
  &lt;/SCRIPT&gt;
  </code></pre>
  
  <p>and I get some error like</p>
  
  <blockquote>
    <p>Uncaught TypeError: Cannot read property 'init' of undefined
    (anonymous function)
    b.extend.ready
    u</p>
  </blockquote>
  
  <p>please help me, how can I resolve this problem? thanks</p>