HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = method;
request.Accept = defaultAcceptHeader;
request.KeepAlive = true;
request.UserAgent = defaultUserAgent;
request.AllowAutoRedirect = false;
request.Headers.Add("Accept-Language", defaultAcceptLanguage);
request.CookieContainer = new CookieContainer();
.Proxy = null;

if(method.Equals("POST", StringComparison.InvariantCultureIgnoreCase))
{
 request.ContentType = @"application/x-www-form-urlencoded";
}

function __doPostBack(eventTarget, eventArgument) {
 var theform;
 if (window.navigator.appName.toLowerCase().indexOf("microsoft") > -1) {
  theform = document.Form1;
　 }
 else {
　  theform = document.forms["Form1"];
 }
 theform.__EVENTTARGET.value = eventTarget.split("$").join(":");
 theform.__EVENTARGUMENT.value = eventArgument;
 theform.submit();
}