在这里,他使用了jqueryvalidator.js并用示例进行了解释.

$.validator.addMethod('IP4Checker',function(value) {
            var ip = "^(?:(?:25[0-5]2[0-4][0-9][01]?[0-9][0-9]?)\.){3}" +
                "(?:25[0-5]2[0-4][0-9][01]?[0-9][0-9]?)$";
                return value.match(ip);
            },'Invalid IP address');

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