function getMessage(messageID) {
      var strMessage = '';
      switch(messageID + '') {
         case '':
         case 'undefined':                { strMessage = ''; break; }
         case 'ERROR_ALREADY_RATED_ITEM': { strMessage = 'You already rated this item.'; break; }
         case 'ERROR_NO_FILE_SELECTED':   { strMessage = 'No file has been selected!'; break; }
         case 'ERROR_NO_RATING':          { strMessage = 'No rating has been submitted!'; break; }
         default: { alert('Error message not found! [' + messageID + ']'); }
      }
      return strMessage;
   }