Qual o erro?

package Inter;
import javax.swing.*;
import java.awt.Event;

public class Interfac extends JFrame {

	public void janela(){
		String nome = "teste";
		JButton botao = new JButton(nome);
		JPanel paine = new JPanel();
		
		paine.add(botao);
		setContentPane(paine);
		
	}
	
	public Interfac() {
		// TODO Auto-generated constructor stub

	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
        
        Interfac a = new Interfac();
        a.janela();

	}

}