When Sending sms to mobile?

When i am sending message to mobile i got an error like below

 

Sender ID Does not Exist or Pending or Route Invalid!

 

i will give the code

 

string strurl = "http://trans.digitelex.in/api/sendmsg.php?user=xxxxxxxx&pass=xxxxx&sender=xxxx&phone=xxxxx&text=TestSMS&priority=ndn&stype=normal";

// Create a request object

WebRequest request = HttpWebRequest.Create(strurl);

// Get the response back

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();

 

I got error like :-

 

Sender ID Does not Exist or Pending or Route Invalid!

 

thanks in advance