Code
<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Default.Master" AutoEventWireup="True"
    CodeBehind="Register.aspx.cs" Inherits="MVCDemo.Views.User.Register" ValidateRequest="False" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
    <title>boy38girl.com</title>
<script type="text/javascript" src="jquery_last.js"></script>
    <script type="text/javascript" src="../../Content/JQuery.Intellisense.js"></script>
    <script type="text/javascript">
        function chk() {
            alert($("#mail").val());
         }
</script>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <li>
            邮箱：
        <input id="mail" name="mail" type="text" onblur="chk();" value="ddddfadf"/><span id="MailImg"></span><span id="MailMsg"></span>
    </li>
    <input type="button" name="Register" id="Register" value="注册" onclick="alert('dd');" />
    

</asp:Content>