[WebMethod]
      [ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)]
      [PrincipalPermission(SecurityAction.Demand, Role = "Users")]
      public void UploadThumbnail(long jobId, string reference, string iconData) {

         byte[] b = Convert.FromBase64String(iconData);

         System.IO.FileStream fs = new System.IO.FileStream(Server.MapPath("/thumbnails/test.jpg"), System.IO.FileMode.CreateNew);
         System.IO.BinaryWriter w = new System.IO.BinaryWriter(fs);

         for(int i=0;i<b.Length;i++) {
            w.Write(b[i]);
         }
         w.Close();
         fs.Close();
      }