HttpWebRequest post提交取得返回值

using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net;
using System.IO;
using System.Text;

namespace hero3
{
    public partial class searchmob : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ASCIIEncoding encoding = new ASCIIEncoding();
            string postData = "mobile=" + Request.QueryString["mob"] + "&action=mobile";
            byte[] data = encoding.GetBytes(postData);

            // Prepare web request
            HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://www.xxx.com/xxx.aspx");

            myRequest.Method = "POST";
            myRequest.ContentType = "application/x-www-form-urlencoded";
            myRequest.ContentLength = data.Length;
            Stream newStream = myRequest.GetRequestStream();

            // Send the data.
            newStream.Write(data, 0, data.Length);
            newStream.Close();

            // Get response
            HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
            StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.Default);
            string content = reader.ReadToEnd();
            string con = content.Substring(content.IndexOf("xxx") + 52, 2);
            Response.Write(con.Trim()); 
        }
    }
}