save cookie after login and use it for login again

Hi , i use this code to login webservice i want to save cookies and login to webservies without user name and password but , i dont know how to save cookies after login ! can any body help me ? thanks

     void Start()
     {
         string urlAdress = URL;
         WWWForm form1 = new WWWForm();
         form1.AddField("username", "username");
         form1.AddField("password", "password");
         Hashtable header = new Hashtable();
         header = form1.headers;
         WWW www = new WWW(urlAdress, form1.data, header);
         StartCoroutine(WaitForRequest(www));
 
     }
 
     IEnumerator WaitForRequest(WWW www)
     {
         yield return www;
 
         // check for errors
         if (www.error == null)
         {
             Debug.Log("WWW Ok!: " + www.data);
 
         }
         else
         {
             Debug.Log("WWW Error: " + www.error);
         }
     }