webBrowser1.Navigate("Targeturl"); // url browsed using get method is used
webBrowser1.Navigate("Targeturl?programcall=60"); // get method is used
//you can also send xml here
string data ="this is test sending by postdata paramer";
byte[] bytedata= Encoding.UTF8.GetBytes(data);
//when you send data using postdata paramer, post method is used
webBrowser1.Navigate("Targeturl", string.Empty, bytedata, string.Empty);