When i am calling the inner jframe, it is called, but outer jframe is not hiding. instead it gets overlapped. so what will be the solution for this. Is there any way to get out of this. As i tried when i am calling the inner class frame, the outer class frame is also called, and it is not hidden.

package com.exp.example;

import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;


@SuppressWarnings("serial")
public class A extends JFrame implements ActionListener {
    JFrame rframe = new JFrame();
    JLabel CFirstName;
    JTextField Cfname;
    JButton jbsubmit;
    Container cp;

    public A() {

        rframe.setSize(500, 200);
        rframe.setLocationRelativeTo(null);
        cp = getContentPane();
        cp.setLayout(null);
        setSize(550, 300);
        rframe.setTitle("Outer Frame");
        cp.setBackground(new Color(140, 180, 180));

        CFirstName = new JLabel("First Name");
        Cfname = new JTextField(10);
        jbsubmit = new JButton("PREVIEW");

        CFirstName.setBounds(10, 20, 100, 35);
        Cfname.setBounds(150, 20, 150, 25);
        jbsubmit.setBounds(190, 110, 92, 25);
        cp.add(CFirstName);
        cp.add(Cfname);
        cp.add(jbsubmit);

        jbsubmit.addActionListener(this);

        rframe.add(cp);
        rframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        rframe.setVisible(true);
    }

    public void actionPerformed(ActionEvent ae) {
        String action = ae.getActionCommand();


        if (action == "PREVIEW") {
            /* Write the code here
             * When we click on preview button the frame of outer class(class A) gets
             * deactivated(closed) and inner frame, frame of inner class(class B) gets visible.
             * it should not be overlapped.  
             */
            /* My Code */
            new B();
            rframe.setVisible(false);

        }
    }

    public class B {
        JFrame frm = new JFrame();
        Container cp;

        public B() {
            frm.setSize(500, 200);
            frm.setLocationRelativeTo(null);
            cp = getContentPane();
            cp.setLayout(null);
            setSize(550, 300);
            frm.setTitle("Inner Frame");
            cp.setBackground(new Color(140, 180, 180));

            JLabel cpn = new JLabel("hello");
            cpn.setBounds(10, 20, 100, 35);
            cp.add(cpn);

            frm.add(cp);
            frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frm.setVisible(true);
        }
    }

    public static void main(String[] args) {
        new A();
    }
}