protected void Button2_Click(object sender, EventArgs e)
 {
     if (Page.IsValid)
     {
         request myRequest = new request();
         bool    add       = myRequest.AddRequest(Session["user"].ToString(), DateTime.Parse(Calendar1.SelectedDate.ToString("yyyy-MM-dd")));
         if (add)
         {
             Button1.Text = "";
             Response.Write("<script>alert('请求发送成功!')</script>");
             BindData();
         }
         else
         {
             Response.Write("<script>alert('请求已经发送过!')</script>");
         }
     }
 }