注册页面中，验证有效合法性

@{
    ViewBag.Title = "注册";
}
<div id="reg">
    <form id="frmregister" class="form-horizontal">
        
        <fieldset>
            <legend class="form-signin-heading">帐号注册</legend>
            <div class="control-group">
                <label class="control-label" for="username">用户名</label>
                <div class="controls">
                    <input type="text" autocomplete="off" class="input-xlarge" name="username" id="username">
                </div>
            </div>
            <div class="control-group">
                <label class="control-label" for="pwd">密码</label>
                <div class="controls">
                    <input type="password" class="input-xlarge" name="pwd" id="pwd">
                </div>
            </div>
            <div class="control-group">
                <label class="control-label" for="pwda">确认密码</label>
                <div class="controls">
                    <input type="password" class="input-xlarge" name="pwda" id="pwda">
                </div>
            </div>
            <div class="control-group">
                <label class="control-label" for="email">电子邮件</label>
                <div class="controls">
                    <input type="text" autocomplete="off" class="input-xlarge" name="email" id="email">
                </div>
            </div>
            <div class="control-group">
                <label class="control-label" for="verifycode">验证码</label>
                <div class="controls">
                    <input type="text" autocomplete="off" class="input-large" name="verifycode" id="verifycode">
                    <img src="/VerificationCode/Index" id="verifycode_img" />
                </div>
            </div>
            <div class="control-group">
                <div class="controls">
                    <button id="register" type="submit" class="btn btn-success">注册</button>
                    <img src="~/Images/loading.gif" id="loding" style="display: none" />
                </div>
            </div>
        </fieldset>
    </form>
    <div style="display: none; margin-left: auto; margin-right: auto; height: 400px;" id="activeinfo">
        <div class="alert alert-success">
            <p>帐号注册成功</p>
            <p>请登录邮箱进行激活帐号</p>
        </div>
    </div>
</div>
@section scripts{
    <script src="~/Scripts/jquery.validate.min.js"></script>
    <script src="~/Scripts/jquery.form.js"></script>
    <script type="text/javascript">

        jQuery.validator.addMethod("username", function (value, element) {
            var val = /^[a-zA-Z][w]{4,11}$/;
            return this.optional(element) || (val.test(value));
        }, "请输入合法用户名");

        jQuery.validator.addMethod("userpwd", function (value, element) {
            var val = /^[w]{6,15}$/;
            return this.optional(element) || (val.test(value));
        }, "密码为6到15位");

        jQuery.validator.addMethod("code", function (value, element) {
            var val = /^[0-9a-zA-Z]{4}$/;
            return this.optional(element) || (val.test(value));
        }, "验证码由4位数字或字母组成");

        $(function () {

            $("#verifycode_img").click(function () {
                showverifycode();
            });

            function showverifycode() {
                var numkey = Math.random() + (new Date().getDate());
                document.getElementById("verifycode_img").src = "/VerificationCode/Index?NumKey=" + numkey;
            }
            $("#frmregister").validate({
                errorClass: "help-inline",
                rules: {
                    username: {
                        required: true,
                        minlength: 5,
                        username: true,
                        remote: {
                            type: "POST",
                            dataType: "json",
                            url: "/Account/UserNameExistOrNot?username=" + $("#username").val()
                        }
                    },
                    pwd: {
                        required: true,
                        minlength: 6,
                        userpwd: true
                    },
                    pwda: {
                        required: true,
                        minlength: 6,
                        equalTo: "#pwd"
                    },
                    email: {
                        required: true,
                        email: true,
                        remote: {
                            type: "POST",
                            dataType: "json",
                            url: "/Account/EmailExistOrNot?email=" + $("#email").val()
                        }
                    },
                    verifycode: {
                        required: true
                    }
                },
                messages: {
                    username: {
                        required: "用户名为空",
                        minlength: "用户名最短长度为5位",
                        remote: "用户名已存在"
                    },
                    pwd: {
                        required: "密码为空",
                        minlength: "密码最短长度为6位"
                    },
                    pwda: {
                        required: "密码为空",
                        minlength: "密码最短长度为6位",
                        equalTo: "两次输入密码不一致"
                    },
                    email: {
                        required: "电子邮件地址为空",
                        email: "电子邮件地址格式错误",
                        remote: "电子邮件地址已存在"
                    },
                    verifycode: {
                        required: "验证码为空"
                    }
                },
                highlight: function (element) {
                    $(element).closest('.control-group').removeClass('success').addClass('error');
                },
                success: function (element) {
                    element
                    .text('OK!').addClass('valid')
                    .closest('.control-group').removeClass('error').addClass('success');
                }
            });

            $('#frmregister').on('submit', function (e) {
                e.preventDefault();
                if ($("#frmregister").valid()) {
                    $(this).ajaxSubmit({
                        type: "post",
                        url: "/Account/RegisterAjax",
                        beforeSend: function () {
                            $("#loding").show();
                        },
                        success: function (msg) {
                            $("#loding").hide();
                            if (msg.Result == "OK") {
                                $("#frmregister").hide();
                                $("#activeinfo").show();

                            } else {
                                alert(msg.Message);
                            }
                        }
                    });
                }
            });
        });
    </script>
}

 学习文档 http://www.runoob.com/jquery/jquery-plugin-validate.html