Problemas com swing

import java.awt.*;
import javax.swing.*;

public class graficos {

	
	public static void main(String[] args) {
	
		int altura = 200;
		int largura = 100;
		int k = 800;
		int y = 600;
		
		JFrame quadro = new JFrame("teste");
		quadro.setSize(altura, largura);
		quadro.setVisible(true);
		quadro.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		
		//************************************
		JPanel principal = new JPanel (new GridBagLayout());
		JPanel novo1 = new JPanel();
		
		//**********************************
		novo1.setBackground(Color.BLUE);
		
		//**********************
		novo1.setLocation(0  , 0);
		
		
		//*************************
		
		JLabel num1 = new JLabel("primeiro numero");
		
		//********************************
		JTextField num = new JTextField(20);
		
		//***************************
		
		novo1.add(num);

	}

}