我已经编写了一个ajax函数，希望在提交表单之前显示确认消息。我应该如何添加我的条件。下面是我的代码。

$.ajax({
                        url: "UBRDashboard.aspx/GetDllValue",
                        dataType: "json",
                        type: "POST",
                        contentType: 'application/json; charset=utf-8',
                        data: JSON.stringify({ ddlOduModel: ddlOduModel, ddlAntModel: ddlAntModel, ddlOMTModel: ddlOMTModel, ddlSapID: ddlSapID, ddlVendorName: ddlVendorName, strReqID: r.d, ddlSapDescVal: ddlSapDescVal, SITE_ADD: SITE_ADD, LATITUDE: LATITUDE, LONGITUDE: LONGITUDE, ddlEQP_SEQ: ddlEQP_SEQ, txtLinkID: txtLinkID, RJ_QUANTITY: RJ_QUANTITY, USER_NAME: USER_NAME, CREATED_DATE: CREATED_DATE, LOCATIONTYPE: LOCATIONTYPE, TOWERTYPE: TOWERTYPE }),
                        async: true,
                        processData: false,
                        cache: false,
                        success: function (r) {
                            if (r.d == "OK") {
                                alert('Record Saved successfully');
                                window.location.href = "UBRDashboard.aspx";
                            }
                        },
                        error: function (xhr) {
                            alert('Error while selecting list..!!');
                            window.location.href = "ErrorPage.aspx";
                        }
                    })
                },
                error: function (xhr) {
                    alert('Error while selecting list..!!');
                    window.location.href = "ErrorPage.aspx";
                }