表单提交数据的方式，以及避免数据重复提交

1.form提交

submit按钮添加一个onsubmit事件：<input type="submit" onsubmit="return checkForm();"/>

             var flag=false;//定义一个标志
             function checkForm(){
               if (flag==true){
                   return false;
               }
              flag=true;
              return true;

             }

2.ajax提交

//ajax提交form表单的方式
        $('#formAddHandlingFee').submit(function() {
            var AjaxURL= "../OrderManagement/AjaxModifyOrderService.aspx";       
            alert($('#formAddHandlingFee').serialize());
                $.ajax({
                    type: "POST",
                    dataType: "html",
                    url: AjaxURL + '?Action=' + 'SubmitHandlingFee' + '&OrderNumber=' + $.trim($("#<%=this.txtOrderNumber.ClientID %>").val()),
                    data: $('#formAddHandlingFee').serialize(),
                    success: function (data) {
                        var strresult=data;
                        alert(strresult);
                        //加载最大可退金额
                        $("#spanMaxAmount").html(strresult);
                    },
                    error: function(data) {
                        alert("error:"+data.responseText);
                     }

                });
        }

       return false;//取消submit按钮提交表单的默认行为

    );