AJAX的问题？？？？怎么不能调用Action？？？

$.ajax({
                             type: "POST",
                              url: "JQueryAction", //请求方向
                              
                              data: {
                                  "scanCode" : $("#saomiaoma").val()

                              }, //json模式的参数 后台使用request.getParamiter截取
                              dataType:"JSON" ,//返回值类型。例如 xml,json,text,html等等
                              success: function(comment){
                                  alert("success");
                                  //本处是处理返回值的js或者jq代码
                                  //如有返回值 在function 后面的括号内加入参数。后台使用response.write方法送到前台
                              }
                          });