public void delete()
    {
        addUndo();
        short tmp = makeArrangementNumber(0, 0, false, false);
        if (isSelectionNull())
        {
            for (int x = 0; x < getTilesWide(); x++)
                for (int y = 0; y < getTilesHigh(); y++)
                    setArrangementData(x, y, tmp);
        }
        else
        {
            for (int x = 0; x < getTilesWide(); x++)
            {
                for (int y = 0; y < getTilesHigh(); y++)
                {
                    if (selection[x][y] != -1)
                    {
                        setArrangementData(x, y, tmp);
                        selection[x][y] = -1;
                    }
                }
            }
        }
        repaint();
        this.fireActionPerformed(new ActionEvent(this,
            ActionEvent.ACTION_PERFORMED, this.getActionCommand()));
    }