Запускаю проэкт и в браузере вижу XML-файл.
Если запустить в WAP-браузере, то выдает ошибку: "нет содержания WML"
Вот код:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.Mobile;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.MobileControls;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Text;
using System.Configuration;

namespace wapunit
{
    /// <summary>
    /// Summary description for _default.
    /// </summary>
    public class _default : System.Web.UI.MobileControls.MobilePage
    {
        protected System.Web.UI.MobileControls.Form Form1;

        private void Page_Load(object sender, System.EventArgs e)
        {
            // Put user code to initialize the page here
            GetDefaultPage();
        }

        private void GetDefaultPage()
        {
            string wml_begin    = ConfigSetting.start_deck;
            string wml_end        = ConfigSetting.end_deck;
            StringBuilder sb    = new StringBuilder();
            int timer            = Int32.Parse(ConfigSetting.GetVal("timer"));

            sb.Append(wml_begin);
            sb.Append("<card id=\"welcome\" title=\"Unitrade\">");            
            sb.Append("<onevent type=\"ontimer\">");
            sb.Append("<go href=\"CodePurchase.aspx\"/>");
            sb.Append("</onevent>");
            sb.Append("<timer value=\""+timer+"\"/>");
            sb.Append("<p align=\"center\">Welcome");
            sb.Append("</p>");
            sb.Append("</card>");
            sb.Append(wml_end);

            Response.ClearContent();
            Response.Clear();
            Response.ContentType = "text/vnd.wap.wml";
            Response.Write(sb.ToString());
            Response.End();

        }

        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {    
            this.Load += new System.EventHandler(this.Page_Load);
        }
        #endregion
    }
}