public GridCell(){
		books = new ArrayList<BookNode>();
		toolTip = new JWindow(new JFrame());
		toolTipContent=new JPanel();
		//toolTip.setBackground(new Color(250,250,178));
		toolTip.setBackground(Color.white);
		toolTip.getContentPane().setBackground(Color.white);
		toolTipContent.setBorder(BorderFactory.createLineBorder(Color.black));
		toolTipContent.setBackground(new Color(250,250,178));
		toolTip.getContentPane().add(toolTipContent);
		toolTip.setVisible(false);
		minX=0; maxX=0; minY=0; maxY =0; xOffset=0; yOffset=0;
	}