Csharp .NET - VS2003 - console application - Webservice request and sending SOAP body



I used soapUI (webservice testing tool) to test thrird party secure ondemand webservice and worked fine and communicating from our proxy. they authenticated our proxy port . but when i deploy .NET console C# client to test, I am not getting response and throwing Internal exception error 500. don't know what i am missing in the following code and looks to me everything is fine.
Note: basic authentication is not required, bcos they onfigured our proxy.

Any help would be great and I really appreciate that. Thanks.


namespace SampleSoapClient
{

class SampleCall
{

[STAThread]
public static void Main(string[] args)
{

HttpWebRequest req =

(HttpWebRequest)WebRequest.Create("https://";);
System.Net.WebProxy myProxy = new System.Net.WebProxy("my-proxy:80",false);
req.Proxy = myProxy;

string soapRequestStr;
soaprequest = " SOAP BODY";
string errMsg;

req.Method = "POST";
req.ContentType = "text/xml";
req.ContentLength = soaprequest.Length;
//req.Accept = "text/xml";


// REQUEST IS FIND AND NOT THROWING ANY EXCEPTION
try
{


Stream myStream = req.GetRequestStream();
StreamWriter sWriter = new StreamWriter(myStream);
sWriter.Write(soapRequestStr);
sWriter.Close();

}
catch(Exception exp)
{
errMsg = "Stream writer object error : " + exp.Message;
Console.WriteLine(errMsg);
}

// RESPONSE IS THROWING EXCEPTION. Internal Web exception error 500

WebResponse resp = null;
StreamReader sReader = null;
string result;


try
{
HttpWebResponse resp = (HttpWebResponse) req.GetResponse();
resp = req.GetResponse();
Stream respStream = resp.GetResponseStream();
sReader = new StreamReader(respStream);
result = sReader.ReadToEnd();
}
catch(Exception ex)
{
errMsg = "Response error : " + ex.Message;
Console.WriteLine(errMsg);
}

} // main
} // class SampleCall
} // namespace

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