imports jquery.min.js imports jquery.validate.min.js [Ajax] function callAjax(){ $.ajax({type: "POST", url: "ajax.asp", data: {fun: "checkCardNO", CardNo: $("#CardNo").val()}, dataType:"html", success:function(msg){ $("#AjaxValue").val(msg); /* Use Hidden input or div to transfer Ajax Value */ } }) } [Form Validation] --Add Validation Function $.validator.addMethod("checkRegisterd", function(value, element) { callAjax(); if($("#AjaxValue").val()=="Unregisted") return true; } ); $.validator.addMethod("Useless", function(value, element) { callAjax(); if($("#AjaxValue").val()!="noData") return true; } ); --Validation $().ready(function() { $("#form1").validate({ rules: { CardNo: { required: true, Useless: true, checkRegisterd: true }, Name: "required", Tel: { require...