Webservice POST to secure site

[Xakware]

Hello All,
I am new to this group, so please forgive me if this
question has been addressed. I have written a function that posts data
to a secure website. It works fine when in a console application or a
form, but the same code fails when used as a web method in a
webservice. The error message says that the number of bytes exceeds
the number of bytes specified in the ContentLength of the httprequest
object. Can anyone help me?? The code is below....


[WebMethod]

public string Send_Req(string strRequest)

{

string result;

HttpWebRequest httpRequest =
(HttpWebRequest)WebRequest.Create("https://www.securesite.com/CGI-BIN/CGIProg.exe");

httpRequest.Method = "POST";

httpRequest.ContentLength = strRequest.Length;

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


X509Certificate myCert =
X509Certificate.CreateFromCertFile(@"C:\test.cer");

httpRequest.ClientCertificates.Add(myCert);


StreamWriter requestWriter = new
StreamWriter(httpRequest.GetRequestStream());

requestWriter.Write(strRequest);

requestWriter.Close();


HttpWebResponse httpResponse =
(HttpWebResponse)httpRequest.GetResponse();

StreamReader resultReader = new
StreamReader(httpResponse.GetResponseStream());

result = resultReader.ReadToEnd();

resultReader.Close();

return result;

}