SEND SMS or Call HttpWebRequest on Proxy Server or ISA Server

Dear All 
I tried to access the HttpWebRequest to send the SMS the code was working fine with my online website but when i run it with my local server and the LAN server i got and server not responding error

Original Solution Post 
http://stackoverflow.com/questions/20336826/httpwebrequest-cannot-connect-through-proxy

A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond IP Address:80
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond IP ADDRESS:80

After quick review of my code i found the issue that my local enviroment is using ISA proxy server and that the main issue that the local intranet environment is throwing following error

Once i do the research i found the above post as a solution with quick hint

1) Add the following lines in your code 
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://www.websiteurl.com");

// This is a problem that the code did not use the proxy
req.Proxy = new WebProxy("[Your Proxy Server Name]", 8080);
req.Proxy.Credentials = new NetworkCredential("User Name", "Password");

Here is the complete code 

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
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;
public partial class _SendSMS : System.Web.UI.Page
{

    private void InitializeComponent()
    {

        this.Load += new System.EventHandler(this.Page_Load);

    }

    private void Page_Load(object sender, EventArgs e)
    {
       
       SendMessage(username, password, message, sender, number);
    }

public string SendMessage(string username, string password, string msg, string sender, string numbers)

    {

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://www.websiteurl.com");

        

        

        req.Method = "POST";

        

        req.ContentType = "application/x-www-form-urlencoded";

    req.Proxy = new WebProxy("[Your Proxy Server Name]", 8080);

req.Proxy.Credentials = new NetworkCredential("User Name", "Password");

        

        string postData = "mobile=" + username + "&password=" + password + "&numbers=" + numbers + "&sender=" + sender + "&msg=" + ConvertToUnicode(msg) + "&applicationType=24";

        req.ContentLength = postData.Length;

        StreamWriter stOut = new

        StreamWriter(req.GetRequestStream(),

        System.Text.Encoding.ASCII);

        stOut.Write(postData);

        stOut.Close();

        // Do the request to get the response

        string strResponse;

        StreamReader stIn = new StreamReader(req.GetResponse().GetResponseStream());

        strResponse = stIn.ReadToEnd();

        stIn.Close();

        return strResponse;

    }

I hope it save your time
Rashid Imran Bilgrami