void jMenuItem_zoom_actionPerformed(ActionEvent e) {
		int zoomFactor = 0;
		if (e.getSource() == jMenuItem_zoom1)
			zoomFactor = 1;
		else if (e.getSource() == jMenuItem_zoom2)
			zoomFactor = 2;
		else if (e.getSource() == jMenuItem_zoom4)
			zoomFactor = 4;
		else if (e.getSource() == jMenuItem_zoom8)
			zoomFactor = 8;
		if (imagemapPanel.zoom(zoomFactor) == false)
			jMenuItem_zoom1.setSelected(true);
		vRule.repaint();
		hRule.repaint();
	}