private void showLoginPanel(){
		JPanel innerPanel = new JPanel();
		innerPanel.setLayout(new BoxLayout(innerPanel, BoxLayout.Y_AXIS));
		
		JLabel userNameLbl = new JLabel("User Name: ");
		JLabel pwdLabel = new JLabel("Password:  ");
		JLabel groupNameLbl = new JLabel("Group Name: ");
		
		JPanel pnl0 = new JPanel();
		errorLabel = new JLabel();
		pnl0.add(errorLabel);
		
		JPanel pnl1 = new JPanel();
		userName = new JTextField();
		userName.setPreferredSize(new Dimension(80, 20));
		pnl1.add(userNameLbl);
		pnl1.add(userName);		
		
		JPanel pnl2 = new JPanel();
		password = new JPasswordField();
		password.setPreferredSize(new Dimension(80, 20));
		pnl2.add(pwdLabel);
		pnl2.add(password);
		
		JPanel pnl4 = new JPanel();
		groupName = new JTextField();
		groupName.setPreferredSize(new Dimension(80, 20));
		groupName.setText("none");
		pnl4.add(groupNameLbl);
		pnl4.add(groupName);
		
		JPanel pnl3 = new JPanel();
		loginBtn = new JButton("Login");
		loginBtn.addMouseListener(new MouseListener() {
			public void mouseReleased(MouseEvent arg0) {}
			public void mousePressed(MouseEvent arg0) {
				if(userName.getText().length() != 0 && password.getPassword().toString().length() != 0 ){
					char[] a = password.getPassword();
					String t = "";
					for(int q = 0;q < a.length;q++){
						t += a[q];
					}
					if(TransSystem.authenticateUser(userName.getText(), t)){
						showDesktop();
					}
					else{
						errorLabel.setText("Login Falied");
						errorLabel.setForeground(Color.RED);
					}
				}
			}
			public void mouseExited(MouseEvent arg0) {}
			public void mouseEntered(MouseEvent arg0) {}
			public void mouseClicked(MouseEvent arg0) {}
		});
		regBtn = new JButton("Register");
		regBtn.addMouseListener(new MouseListener() {
			public void mouseReleased(MouseEvent arg0) {}
			public void mousePressed(MouseEvent arg0) {
				if(userName.getText().length() != 0 && password.getPassword().toString().length() != 0 ){
					char[] a = password.getPassword();
					String t = "";
					for(int q = 0;q < a.length;q++){
						t += a[q];
					}
					if(TransSystem.registerUser(userName.getText(), t, groupName.getText())){
						showDesktop();
					}
				}
			}
			public void mouseExited(MouseEvent arg0) {}
			public void mouseEntered(MouseEvent arg0) {}
			public void mouseClicked(MouseEvent arg0) {}
		});
		pnl3.add(loginBtn);
		pnl3.add(regBtn);
		
		innerPanel.add(pnl0);
		innerPanel.add(pnl1);
		innerPanel.add(pnl2);
		innerPanel.add(pnl4);
		innerPanel.add(pnl3);
		loginPanel.add(innerPanel);
		loginPanel.revalidate();
	}