abt java project

this program compile sucessfully but data is not store in data base if any thing correction plz do it

import java.awt.*;
import javax.swing.*;
import java.sql.*;
import java.awt.event.*;
public class simple extends JFrame implements ActionListener{

private static final long serialVersionUID = 1L;
JLabel label1,label2,label3;
JTextField textfield1,textfield2;
JPasswordField pass;
JButton button1,button2;
JPanel panel;
public simple()
{
label1=new JLabel("user Name");
textfield1=new JTextField(15);
label2=new JLabel("Password");
pass=new JPasswordField(15);
label3=new JLabel("address");

textfield2=new JTextField(15);

button1=new JButton("SAVE");
button2=new JButton("cancel");
panel=new JPanel(new GridLayout(15,2));
panel.add(label1);
panel.add(textfield1);
panel.add(label2);
panel.add(pass);
panel.add(label3);

panel.add(textfield2);

panel.add(button1);
panel.add(button2);
button1.addActionListener(this);
button1.setActionCommand("SAVE");

//button1.addActionListener(new ActionListener());
add(panel);
setSize(300,400);
setVisible(true);


}

public void actionPerformed(ActionEvent ae) {
String cmd=ae.getActionCommand();
if (cmd.equalsIgnoreCase("SAVE")){


String value1=textfield1.getText();
String value2=textfield2.getText();
String value3=pass.getText();

Connection con=null;
Statement stm=null;
String user1="";
try
{
Class.forName("org.postgresql.Driver");
con = DriverManager.getConnection("jdbc:postgresql://localhost" + "/smp", "postgres", "postgres");
stm=con.createStatement();
ResultSet res=stm.executeQuery("select *from register where username="+value1+"");
System.out.print("query executed");
if(res.next())
{
user1=res.getString("username");
JOptionPane.showMessageDialog(null,"invalid userName");
}
else
{
stm.execute("insert into register values('" +value1+ "','" +value2+ "','"+value3+"')");
JOptionPane.showMessageDialog(null, "Data successfully saved");

}
}
catch(Exception e)
{

}




}
}
public static void main(String arg[])
{
simple smp=new simple();
}

}