jQuery Validation - IP Address validation problems

Question

I have developed code of how to validate IP Address.

Script

<script type="text/javascript"
    src="http://ajax.microsoft.com/ajax/jQuery/jquery-1.4.2.min.js">
    </script>
    <script type="text/javascript" src=
"http://ajax.microsoft.com/ajax/jquery.validate/1.7/jquery.validate.min.js">
    </script>
    <script type="text/javascript">
        $(function() {
            $.validator.addMethod('IP4Checker', function(value) {
            var ip = "^(?:(?:25[0-5]2[0-4][0-9][01]?[0-9][0-9]?)\.){3}" +
                "(?:25[0-5]2[0-4][0-9][01]?[0-9][0-9]?)$";
                return value.match(ip);
            }, 'Invalid IP address');

            $('#form1').validate({
                rules: {
                    ip: {
                        required: true,
                        IP4Checker: true
                    }
                }
            });

        });
    </script>

HTML

    <input id="ip" name="ip" type="text"  /> 
    <input id="Submit1" type="submit" value="submit" />

This script is working good but have one problem this script only check the IP block 0-255 numbers when i enter 100.100.100 it accept the IP address also when I enter any numeric value like 1234567 it also accept this value as IP address. so please help me regarding this problem

Thanks