How To Integrate sms gateway api Into My website

string strUrl =  "http://api.mVaayoo.com/mvaayooapi/MessageCompose?user=username&senderID=yourid&receipientno=mobilno&msgtxt=This is a test API&state=4"; 
WebRequest request = HttpWebRequest.Create(strUrl);
HttpWebResponse response = (HttpWebResponse)request.GetResponse(); 
Stream s = (Stream)response.GetResponseStream();
StreamReader readStream = new StreamReader( s );
string dataString = readStream.ReadToEnd();
response.Close();
s.Close();
readStream.Close();