title: how to read multi-levels json format using jquery
body: <p>i have a json format like</p>
  
  <pre><code>[
      {
          id: 15,
          diemdung: "a"
      },
      {
          id: "16",
          diemdung: "b",
          khoangcach: "300",
          pho: "c",
          da: [
              {
                  lancan: "d",
                  kc: "333"
              },
              {
                  lancan: "e",
                  kc: "322"
              }
          ]
      },
      ...
  ]
  </code></pre>
  
  <p>i using php like <code>print json_encode($rows);</code><br>
  and i try to read it at client using jquery like</p>
  
  <pre><code>$.getJSON(url,function(json){
      $.each(json,function(key, val){
          $.each(this.da,function(){
              alert(this.kc);
          });
      });
  });
  </code></pre>
  
  <p>but it's not working. How i do that? thanks</p>