how to exit upper frame by click on ok and how to add back button when two page in single frame

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class Prhr extends JFrame implements ActionListener,ItemListener
{
    JLabel l1;
    JLabel l2;
    JTextField ar;
    JTextField t;
    JButton b1;
    JButton b2;
    JButton b3,b4;
    JComboBox c1,c2;
    JLabel l3;
    Connection con;
    Statement st;
    JLabel l4;
    JLabel l5;
    JLabel l6;
    JLabel l7,l8,l9,l10,l11,l12,l13;
    Font f,f2,f1;
    String s3,s4;
    public Prhr()
    {
        c1=new JComboBox();
        c1.addItem("....");
        //*****************************************
        try{
            System.out.println("in");
            Class.forName("com.mysql.jdbc.Driver");
            con=DriverManager.getConnection("jdbc:mysql://localhost:3306/amit","root","1234");
            System.out.println(con);
            st=con.createStatement();
            System.out.println(st);
            ResultSet rs= st.executeQuery("select * from CHR");
            while(rs.next())
            {   
                c1.addItem(rs.getString("prnm"));

            }

        }catch(Exception e1)
        {
            e1.printStackTrace();
        }
    //****************************************

    //JPanel p=new JPanel();
    //j.add(p);
        f2=new Font("Tahoma", 1, 20);
        setFont(f2);
        setTitle("CREATE PROCESS HIERARCHY");
        f1=new Font("Tahoma", 1, 18);
        //setFont(f1);
    l1=new  JLabel("Process Name");
    l2=new JLabel("Description");
    l3=new JLabel("Provide Process Detail");
    l8=new JLabel("Parent Process");
    l9=new JLabel("Processs Type");
    ar=new JTextField();
    t=new JTextField();

    c2=new JComboBox();
    b1=new JButton("Preview & Save");
    b2=new JButton("Clear");
    b3=new JButton("Save as Draft");
    setLayout(null);
    f=new Font("Tahoma", 1, 20);
    //c1.addItem("....");
    c2.addItem("Process");
    //c1.addItem("1c1");
    //c1.addItem("2c1");
    c2.addItem("Activity");
    //c2.addItem("2c2");
    add(l3);
    l3.setBounds(170, 70, 250, 20);
    add(l1);
    l3.setFont(f1);
    l1.setBounds(100,130,100,20);
    add(t);
    t.setBounds(210, 130, 200, 20);
    add(l2);
    l2.setBounds(100, 175, 100, 20);
    add(l8);
    l8.setBounds(100, 240, 100, 20);
    add(l9);
    l9.setBounds(100, 285, 100, 20);
    add(ar);
    ar.setBounds(210, 175, 200, 40);
    add(c1);
    c1.setBounds(210, 240, 200, 20);
    add(c2);
    c2.setBounds(210, 285, 200, 20);
    add(b1);
    b1.setBounds(50, 365, 129, 20);
    add(b2);
    b2.setBounds(220, 365, 70, 20);
    add(b3);
    b3.setBounds(340, 365, 120, 20);
    b1.addActionListener(this);
    b2.addActionListener(this);
    b3.addActionListener(this);
    c1.addItemListener(this);
    c2.addItemListener(this);
    t.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent e) {
          char c = e.getKeyChar();
          if (!((c >= 65) && (c <= 90)||(c>=97)&&(c<=122) ||
             /*(c == KeyEvent.VK_BACK_SPACE) ||*/(c==32)||
             (c == KeyEvent.VK_DELETE))) {
           // getToolkit().beep();
            e.consume();
          }
        }
      });
    ar.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent e) {
          char c = e.getKeyChar();
          if (!((c >= 65) && (c <= 90)||(c>=97)&&(c<=122) ||
             /*(c == KeyEvent.VK_BACK_SPACE) ||*/(c==32)
             )) {
           // getToolkit().beep();
            e.consume();
          }
        }
      });
    //b4.addActionListener(this);


    }
    public void itemStateChanged(ItemEvent ie)
    {
        s3=(String)c1.getSelectedItem();
        System.out.println(s3);
        s4=(String)c2.getSelectedItem();
        System.out.println(s4);
    }
    public void actionPerformed(ActionEvent a)
    {
        if(a.getSource()==b1)
        {
                System.out.println("in b1");

                    final String s1=t.getText();
                    final String s2=ar.getText();
                    int q=s1.length();
                    int w=s2.length();
                    if(q<=20||q>0&&w<=200||w>0)
                    {
                    System.out.println(s3);
                    System.out.println(s4);
                    JFrame j=new JFrame();
                    j.setVisible(true);

                    //j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    j.setSize(500,500);
                    JPanel p=new JPanel();
                    j.add(p);
                    p.setLayout(null);
                     l4=new JLabel("Process Name");
                    l5=new JLabel(s1);
                    l6=new JLabel("Description");
                    l7=new JLabel(s2);
                    l10=new JLabel("Parent Process");
                    l11=new JLabel(s3);
                    l12=new JLabel("Process Type");
                    l13=new JLabel(s4);
                    b4=new JButton("OK");

                    p.add(l4);
                    l4.setBounds(100,130,100,20);
                    p.add(l5);
                    l5.setBounds(210, 130, 200, 20);
                    p.add(l6);
                    l6.setBounds(100, 175, 100, 20);
                    p.add(l7);
                    l7.setBounds(210, 175, 200, 40);
                    p.add(l10);
                    l10.setBounds(100, 240, 100, 20);
                    p.add(l11);
                    l11.setBounds(210, 240, 200, 20);
                    p.add(l13);
                    l13.setBounds(210, 285, 200, 20);
                    p.add(l12);
                    l12.setBounds(100, 285, 100, 20);
                    p.add(b4);

                    b4.setBounds(220, 365, 70, 20);

                    //**************88
                    b4.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent d) {

                    if(d.getSource()==b4)
                    {
                        //System.exit(1);
                        dispose();
                        try
                        {   
                        dispose();
                        System.out.println("in");
                        Class.forName("com.mysql.jdbc.Driver");
                        con=DriverManager.getConnection("jdbc:mysql://localhost:3306/amit","root","1234");
                        System.out.println(con);
                        st=con.createStatement();
                        System.out.println(st);
                        int i=st.executeUpdate("insert into CHR values('"+s1+"','"+s2+"','"+s3+"','"+s4+"')"); 
                        if(i>1)
                        {
                            con.close();
                            st.close();

                        }
                        //setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                            System.out.println("inserted");

                            ResultSet rs= st.executeQuery("select * from CHR");
                            while(rs.next())
                            {   
                                c1.addItem(rs.getString("prnm"));

                            }



                            }catch(Exception e)
                            {
                                e.printStackTrace();
                            }
                            //j.dispose();

                    }//b4 if close
                        }


                    });

                    }
                    else
                    {
                         String message = "\"Pls enter Name within 20 Chatarter\"\n"
                                + "OR\n"
                                + "Pls enter Description within 200 character";;
                        JOptionPane.showMessageDialog(new JFrame(), message, "Dialog",
                                JOptionPane.ERROR_MESSAGE);
                    }
        }
        else if (a.getSource()==b2)
        {
            System.out.println("in b2");
            t.setText("");
            ar.setText("");
            c1.setSelectedItem("....");
            c2.setSelectedItem("Process");
        }
        else if(a.getSource()开发者_运维百科==b3)
        {
            System.out.println("in b3");
        }
    }
    public static void main(String args[])
    {
    Prhr pr=new Prhr();
        pr.setVisible(true);
        pr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pr.setSize(500,500);
    }

}

I see in your actionPerformed method you are creating a new JFrame. I assume that is the second frame you are talking about. You might want to use a JDialog, but hard to say since I've no idea what your app does.

But to answer your question, to close a JFrame call:

j.setVisible(false);