public boolean removeGrid(final Grid grid){
  final boolean result=gridList.remove(grid);
  if (result) {
    remove(grid);
    revalidate();
  }
  return result;
}

public boolean removeGrid ( final Grid grid ) { final boolean result = gridList . remove ( grid ) ; if ( result ) { remove ( grid ) ; revalidate ( ) ; } return result ; }
remove a grid from the plot area .
