private void jB_voltarActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jB_voltarActionPerformed
        try {
            Principal principal = new Principal();
            principal.setExtendedState(JFrame.MAXIMIZED_BOTH);
            Toolkit theKit = principal.getToolkit(); // for Fullscreen  
            principal.setBounds(new Rectangle(theKit.getScreenSize()));
            principal.setVisible(true);
            this.dispose();
        } catch (Exception e) {
        }
    }//GEN-LAST:event_jB_voltarActionPerformed