Java SE (Java Platform, Standard Edition)

I run the following code as s5.java

import javax.swing.*;
import java.awt.*;
//<applet code="s5.class" width=300 height=400></applet>

public class s5 extends JApplet
{
	JPanel colpanel, logpanel, mainpanel;
	JLabel l,l1,l2;
	JButton b,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14;
	JTextField t,t1,t2;
	
	GridBagLayout gbl;
	GridLayout g1;
	GridBagConstraints gbc;
	BoxLayout bl;
	
	public void init()
	{
		b = new JButton("Login");
		g1 = new GridLayout(8,2);
		colpanel = new JPanel();
		colpanel.setLayout(g1);
		
		gbl = new GridBagLayout();
		gbc = new GridBagConstraints();
		logpanel = new JPanel();
		logpanel.setLayout(gbl);
		
		l = new JLabel("Calculator Panel");
		t = new JTextField(10);
		b1 = new JButton("1");
		b2 = new JButton("2");
		b3 = new JButton("3");
		b4 = new JButton("4");
		b5 = new JButton("5");
		b6 = new JButton("6");
		b7 = new JButton("7");
		b8 = new JButton("8");
		b9 = new JButton("9");
		b10 = new JButton("+");
		b11 = new JButton("-");
		b12 = new JButton("/");
		b13 = new JButton("*");
		b14 = new JButton("CALCULATE");
		
		l1 = new JLabel("Customer Login Name");
		l2 = new JLabel("Password");
		
		t1 = new JTextField(10);
		t2 = new JTextField(10);
		//t = new JTextField(19);
		
		gbc.anchor = GridBagConstraints.NORTHWEST;
		gbc.gridx = 1;
		gbc.gridy = 5;
		gbl.setConstraints(l1,gbc);
		logpanel.add(l1);
		
		gbc.anchor = GridBagConstraints.NORTHWEST;
		gbc.gridx = 4;
		gbc.gridy = 5;
		gbl.setConstraints(t1,gbc);
		logpanel.add(t1);
		
		gbc.anchor = GridBagConstraints.NORTHWEST;
		gbc.gridx = 1;
		gbc.gridy = 8;
		gbl.setConstraints(l2,gbc);
		logpanel.add(l2);
		
		gbc.anchor = GridBagConstraints.NORTHWEST;
		gbc.gridx = 4;
		gbc.gridy = 8;
		gbl.setConstraints(t2,gbc);
		logpanel.add(t2);
		
		gbc.anchor = GridBagConstraints.NORTHWEST;
		gbc.gridx = 3;
		gbc.gridy = 11;
		gbl.setConstraints(b,gbc);
		logpanel.add(b);
		
		colpanel.add(l);
		colpanel.add(t);
		colpanel.add(b1);
		colpanel.add(b2);
		colpanel.add(b3);
		colpanel.add(b4);
		colpanel.add(b5);
		colpanel.add(b6);
		colpanel.add(b7);
		colpanel.add(b8);
		colpanel.add(b9);
		colpanel.add(b10);
		colpanel.add(b11);
		colpanel.add(b12);
		colpanel.add(b13);
		colpanel.add(b14);
		
		mainpanel = new JPanel();
		bl = new BoxLayout(mainpanel,BoxLayout.X_AXIS);
		bl.addLayoutComponent("Calculator" , colpanel);
		bl.addLayoutComponent("Information" , logpanel);
		getContentPane().add(mainpanel);
		mainpanel.add(colpanel);
		mainpanel.add(logpanel);		
	}
}

It gets compiled properly. But when I run it using appletviewer, it shows an error saying BoxLayout Can't be shared.

I am using JDK 6.