Java - llamar jdialog desde un jframe

JButton btnProvedores = new JButton("PROVEDORES");

btnProvedores.addActionListener(new ActionListener() {

    public void actionPerformed(ActionEvent arg0) {

        provedores dialog = new provedores();

                dialog.setVisible(true);

    }

});

JButton btnProvedores = new JButton("PROVEDORES");

btnProvedores.addActionListener(new ActionListener() {

    public void actionPerformed(ActionEvent arg0) {

         executeWindows();

    }

});

public void executeWindows(){

    Provedores dialog = new Provedores();

                dialog.setVisible(true);

}

new Jdialog(this, true).setVisible(true);