Web Service Call Confirmation

Basically I want some sort of confirmation from mobile end that my executed service call worked perfectly. At present I am using following code for using particular web service.

     WWW www = new WWW (url);
 
     //Load the data and yield (wait) till it's ready before we continue executing the rest of this method.
     yield return www;
 
     if (www.error == null) {
         //Sucessfully loaded the XML
         Debug.Log ("Loaded following XML " + www.text);
     } else {
         Debug.Log ("ERROR: " + www.error);
     }

As well after call this service, I have following kind of response from web server.

So my question is, to get confirmation about web service call runs successful or not, whether I need to parse web server response? Or any other clever mechanism exist to check successful status of web service called.

Please give me some suggestion in this.