import java.awt.*;
import java.applet.*;
import java.net.*;
import java.awt.event.*;
public class ConnectApplet extends Applet implements ActionListener
{
	TextField textField;//聲明一個文本框
	boolean badURL;//聲明非法網址
	public void init()
	{
		Button button=new Button("Go"); 
		add(button);//添加一個按鈕
		button.addActionListener(this);//添加按鍵事件
		textField=new TextField("",30);//添加文本框，長度為30
		add(textField);
		badURL=false;
	}
	public void paint(Graphics g)
	{if (badURL)
	g.drawString("Bad url!",60,130);//如果非法，則顯示提示
	}
	public void actionPerformed(ActionEvent evt)
	{
		String str=textField.getText();
		try
		{
			URL url=new URL(str);
			AppletContext context=getAppletContext();
			context.showDocument(url,"_blank");//新建一個窗口轉入網頁
		}
		catch(MalformedURLException e)
		{
			badURL=true;
			repaint();
		}
	}
}