import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.Dimension;

public class AppletTest1 extends Applet{

    public void paint(Graphics g){
        g.setColor(Color.red);

        Dimension size = getSize();
        g.fillRect(0, 0, size.width - 1, size.height - 1);
    }

}