public void mouseReleased(MouseEvent me)
    {
        int x = me.getX()
            / (getTileSize() * getZoom() + (isDrawGridLines() ? 1 : 0));
        int y = me.getY()
            / (getTileSize() * getZoom() + (isDrawGridLines() ? 1 : 0));
        if (me.getButton() == MouseEvent.BUTTON1)
        {
            if ((me.getModifiers() & MouseEvent.ALT_MASK) != 0)
            {
                selection = createNewSelection(x, y);
                repaint();
            }
            else if ((me.getModifiers() & MouseEvent.CTRL_MASK) != 0)
            {
                selt = -1;
            }
        }
    }