// TestTextField.java
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class TestTextField extends JFrame implements ActionListener{
 JLabel p; 
 JTextField in; 
 JLabel out; 
 String s="";
	public MyFrame()	{
	 p=new JLabel ("请输入口令: ");
	 in=new JTextField(18);
	 out=new JLabel();
	 this.getContentPane().setLayout(new FlowLayout());
	 this.getContentPane().add(p);	 
	 this.getContentPane().add(in); 
	 this.getContentPane().add(out);
 in.addActionListener(this);
	}
 	public void actionPerformed(ActionEvent evt) 	{ 
 s=in.getText();
	 if(s.equals("MyKey")) 
	 	out.setText("通过!");
 else 
 	out.setText("口令错!");
 	}
	public static void main(String[] args)	{
		TestTextField textField = new TestTextField ();
		textField.setTitle("Show");
		textField.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		textField.setSize(250,250);
		textField.setVisible(true);
	}
}