import java.awt.Graphics;
import javax.swing.JPanel;

public class FirstDrawing extends JPanel
{
	public void paintComponent(Graphics g)
	{
		//this MUST be the first line in your paintComponent method
		super.paintComponent(g);

		final int WIDTH = getWidth(); 	//getWidth() returns the width of the current panel
		final int HEIGHT = getHeight();	//getHeight() returns the height of the current panel

		g.drawLine(0,0,		 WIDTH,HEIGHT);
		g.drawLine(0,HEIGHT, WIDTH,0);
		g.drawLine(WIDTH/2, 0, WIDTH/2, HEIGHT);
		g.drawLine(0, HEIGHT/2, WIDTH, HEIGHT/2);

	} //end method paintComponent

} //end class FirstDrawing