JavaScript IP address validation

IP address validation in JavaScript is used to ensure that the number entered in the specified IP address field should be a valid IP address.

Regular Expression:

/^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)
\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/

Example:

<!DOCTYPE html>
<html lang="en">
<head>
<script>
function ipAddressCheck(ipAddress)
{
var regEx = /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)
\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
if(ipAddress.value.match(regEx))
{
return true;
}
else
{
alert("Please enter a valid ip Address.");
return false;
}
}
</script>
</head>
<body>
<div class="mail">
<h2>JavaScript IP Address Validation</h2>
<form name="form1" action="#">
IP Address: <input type='text' name='ipAddress'/></br></br>
<input type="submit" name="submit" value="Submit"
onclick="ipAddressCheck(document.form1.ipAddress)"/>
</form>
</div>
</body>
</html>