How can I call cardlayout.show from another class?

Question

I'm trying to call the method cardlayout.show to class below.

protected void makelabeltxt(final String text, GridBagLayout gridbag, GridBagConstraints c, int width, int height, final String panel) {
    final JLabel label = new JLabel(text);              
    Dimension d = new Dimension(width, height);
    gridbag.setConstraints(label, c);
    label.setFont(new Font("Sans Serif", 0, 11));
    label.setPreferredSize(d);


    label.addMouseListener(new MouseListener() {

        @Override
        public void mouseClicked(MouseEvent e) {                
            System.out.println(panel);
            fp.showPanel(panel);
            System.out.println("mouse clicked "+text);
        }

        @Override
        public void mousePressed(MouseEvent e) {
            label.setText("  " + text);
            System.out.println("mouse pressed "+text);
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            label.setText(" " + text);
            System.out.println("mouse release "+text);
        }

        @Override
        public void mouseEntered(MouseEvent e) {
            label.setText(" " + text);
            System.out.println("mouse entered "+text);
        }

        @Override
        public void mouseExited(MouseEvent e) {
            label.setText(text);

        }
    });
    add(label);
}

In another class I've created method like this, this is the method i want to call. I want to swap jpanel, but in another jpanel: the method below is working but when cardlayout show script, it's nothing happen, the println script is fine

public void showPanel(String panel){
    System.out.println("panel : "+panel);       
    cl.show(mainInPanel, panel);
}

this is how i add JPanel to JPanel using cardlayout

public void initPanelFrm(JPanel panel, String gambar) {             
        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints gbc = new GridBagConstraints();
        panel.setLayout(gridbag);
        panel.setPreferredSize(new Dimension(810, 280));
        panel.setBackground(Color.white);
        makelabelimg("com/reporting/image/"+gambar+".png", 444, 23, panel);     
        panel.setVisible(false);
        mainInPanel.add(panel, gambar); 
    }

    public void initInPanel(){
        rekappenjualanpsc = new JPanel();
        initPanelFrm(rekappenjualanpsc, "rekappenjualanpsc");
        rekapbastudenganmaskapai = new JPanel();
        initPanelFrm(rekapbastudenganmaskapai, "rekapbastudenganmaskapai");
        rekapitulasisetoranmaskapai = new JPanel();
        initPanelFrm(rekapitulasisetoranmaskapai, "rekapitulasisetoranmaskapai");
        rekappenjualanpscpermaskapai = new JPanel();
        initPanelFrm(rekappenjualanpscpermaskapai, "rekappenjualanpscpermaskapai");
        rekappungutanlangsungpsc = new JPanel();
        initPanelFrm(rekappungutanlangsungpsc, "rekappungutanlangsungpsc");
        laporandetailpetugas = new JPanel();
        initPanelFrm(laporandetailpetugas, "laporandetailpetugas");
        detailpembayaranpenumpang = new JPanel();
        initPanelFrm(detailpembayaranpenumpang, "detailpembayaranpenumpang");

    }