ตรวจสอบค่าที่ต้อง Require ก่อน Submit ครับ

Code:Header

<script language="Javascript"><!--

function validatefrm(){	var theForm = document.frmAdd;

 var errMsg = "";

 var setfocus = "";

if (theForm['Fname'].value == ""){

 	errMsg = "ชื่ออ่ะ";

 	setfocus = "['Fname']";

 }

 if (theForm['Lname'].value == ""){

 	errMsg = "นามสกุลอ่ะ";

 	setfocus = "['Lname']";

 }

if (errMsg != ""){

 	alert(errMsg);

 	eval("theForm" + setfocus + ".focus()");

 }

 else theForm.submit();

}

</script>

Code:Body

<form action="" method="post"  name="frmAdd" id="frmAdd" onSubmit="validatefrm();return false;">
Fname :<input name="Fname" type="text" id="Fname"><br />
Lname :<input name="Lname" type="text" id="Lname" >
<input name="Submit" type="submit">
</form>