jquery下拉列表

function roomF() {
              var option4 = "<OPTION value='";
              var option5 = "'>";
              var option6 = "</OPTION>";
              $.post("<c:url value="/rooms/selectResultRoomId.do"/>",{stageId: $("#stage_id").val()} ,function(xml) {
                  document.getElementById("room_id").innerHTML = '';
                  $(xml).find("select").each(function() {
                      var value = $(this).children("value").text();
                      //取文本
                      var text = $(this).children("text").text();
                      //取文本
                      //          $(this).attr("email"); 这里能显示属性。
                      if (value == '<%=room_id%>') {
                          $("#room_id").append("<option value='" + value + "' selected >" + text + "</option>");
                      } else {
                          $("#room_id").append(option4 + value + option5 + text + option6);
                      }
                  });
              });
          }