如何在javascript里解析json数据

({status:0,
  errorMessage:"",
  retryCode:51,
  data:[
         {"root":[
                   {"head":{"REH_BOTEL":"","REH_DFAX":""},"body":[{"RED_PHO_FIL":"","RED_STAX_AMT":""}]},
                   {"head":{"REH_BOTEL":"","REH_DFAX":""},"body":[{"RED_PHO_FIL":"","RED_STAX_AMT":""}]}
         ]}
       ],
  count:3
})
上面是java生成的json数据怎么取得dada里面的数据？像取得status就直接用json.status就可以，但 data里面又包含有数组，该怎么取请问 在jsp:代码中
$.getJSON(url,
     function(json){
       var results = json.status;
      if(results =="1" || results=="2") {
        document.all["error"].innerHTML=json.errorMessage;
          } else {
              var str = "({";
              str += "status:" + json.status + ",";
              str += "errorMessage:\"" + json.errorMessage + "\",";
              str += "retryCode:" + json.retryCode+",";
              str += "data:" + json.data[0] +",";
              str += "count:" + json.count + "";
              str += "})";         
          }
});