Asp.net用ajax实现无刷新提交


Send.aspx<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Send.aspx.cs" Inherits="Send" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server"> 
    <title>无标题页 </title> 
    <script type="text/javascript"> 
        function SendData() 
        { 
            var seat="S006";    
            var xh = new ActiveXObject("MSXML2.XMLHTTP");  
            xh.open("POST","Do.aspx",false); 
            xh.send(document.all.txtUser.value);  
        } 
    </script> 
</head> 
<body> 
    <form id="form1" runat="server" method="post"> 
        <div> 
            <input id="txtUser" type="text" runat="server" /> 
            <input id="Button1" type="button" value="button" onclick="SendData()"/> 
        </div> 
    </form> 
</body> 
</html> Do.aspx.cspublic partial class Do : System.Web.UI.Page 
{ 
    protected void Page_Load(object sender, EventArgs e) 
    {         SqlConnection con = new SqlConnection("Data Source=7E2DF151D5144A0\\SQLEXPRESS;Initial Catalog=TicketBook;Integrated Security=True"); 
        con.Open(); 
        SqlCommand cmd = new SqlCommand("update Seat set i_SeatState =@seatState where c_SeatCode=@seatCode", con); 
        cmd.Parameters.AddWithValue("@seatState", "1"); 
        cmd.Parameters.AddWithValue("@seatCode", "S006"); 
        cmd.ExecuteNonQuery(); 
        con.Close(); 
    } 
}但是数据库里面没有改变，就是说Do.aspx没有执行，哪里错了呢？