By using the regular expression "/^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/" we can validate the email in JavaScript.
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Email ID
Validation Using JavaScript Regular Expression.</title>
<script language="javascript">
function
ValidateEmailID(txtEmailID) {
var
filter =
/^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
if
(txtEmailID.value == "") {
txtEmailID.style.border = "";
return
true;
}
else
if (filter.test(txtEmailID.value)) {
txtEmailID.style.border = "";
return
true;
}
else
{
txtEmailID.style.borderColor = "red";
return
false;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
Enter Email ID :
<input type="text" onkeyup="ValidateEmailID(this);" />
</div>
</form>
</body>
</html>