public String getToolTipText( MouseEvent e )
  {
    String tip = null ;
    java.awt.Point p = e.getPoint() ;
    int rowIndex = rowAtPoint( p ) ;
    int colIndex = columnAtPoint( p ) ;
    int realColumnIndex = convertColumnIndexToModel( colIndex ) ;

    if ( realColumnIndex == 0 ) // comments
    {
      TMultiLanguageEntry entry = ( TMultiLanguageEntry )
                                 param.getModel().getValueAt( rowIndex, 0 ) ;
      int t = entry.sizeOfValidations() ;
      if ( t < 1 )
      {
        tip = null ;
      }
      else if ( t > 1 )
      {
        tip = Integer.toString( t ) + "validation hints" ;
      }
      else
      {
        tip = "1 validation hint" ;
      }

      if ( entry.hasComment() )
      {
        if ( tip == null )
        {
          // tip = "comment available" ;
          tip = "comment available [" + entry.getCommentsInfo() + "]" ;
        }
        else
        {
          tip += "and a comment available" ;
        }
      }
    }
    else if (realColumnIndex == 1)
    {
      TMultiLanguageEntry entry = ( TMultiLanguageEntry )
                                 param.getModel().getValueAt( rowIndex, 0 ) ;
      if (entry != null)
      {
//        if (entry.getKeyRef().getReferenceCount() > 0)
        {
          tip = "number of references found in source code" ;
        }
      }
      else tip = null ;
    }
    else
    {
      //You can omit this part if you know you don't
      //have any renderers that supply their own tool
      //tips.
      tip = super.getToolTipText( e ) ;
    }
    return tip ;
  }