import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import java.net.*;
public class lab9 extends Applet implements ActionListener
{
	private TextField TF1, TF2, TF3, TF4, TF5, tf;
	private Button compute, clear, go;
	private Label L1, L2, L3, L4, L5;
	private URL site;
	public void init()
	{
		setLayout(new FlowLayout());
		add(L1 = new Label("Loan Amount"));
		add(TF1 = new TextField(10));
		add(L2 = new Label("Years"));
		add(TF2 = new TextField(10));
		add(L3 = new Label("Yearly Interest Rate"));
		add(TF3 = new TextField(10));
		add(L4 = new Label("Total Amount"));
		add(TF4 = new TextField(10));
		add(L5 = new Label("Monthly Payment"));
		add(TF5 = new TextField(10));
		add(compute = new Button("Compute"));
		add(clear = new Button("Clear"));
		add(tf = new TextField("http://members.fortunecity.com/blackscrol", 50));
		add(go = new Button("GO"));
		go.addActionListener(this);
	
	//	TF5.setEditable(false);
	//	TF4.setEditable(false);
		compute.addActionListener(this);
		clear.addActionListener(this);
		TF3.addActionListener(this);
	}
	public void Compute() throws NegativeNumberException, DivideByZeroException
	{
		double Amt, Rate, Years, mr, mp;
		int m;
		Amt = Double.valueOf(TF1.getText().trim()).doubleValue();
		Years = Integer.valueOf(TF2.getText().trim()).intValue();
		Rate = Double.valueOf(TF3.getText().trim()).doubleValue();
		if((Amt == 0)||(Rate == 0)||(Years == 0))
		{
			throw new DivideByZeroException();
		}
		if((Amt < 0)||(Rate < 0)||(Years < 0))
		{
			throw new NegativeNumberException();
		}
		m = (int) Years*12;
		mr = (Rate/12)*.01;
		TF4.setText("$" + Double.toString((mp = (Amt * mr)/(1 - (Math.pow((1/(1+mr)),m))))));
		TF5.setText("$" + Double.toString((mp*m)));
	}
	public void clearAll()
	{
		TF1.setText(" ");
		TF2.setText(" ");
		TF3.setText(" ");
		TF4.setText(" ");
		TF5.setText(" ");
	}
	public void actionPerformed(ActionEvent ae)
	{
		Object src = ae.html
		
		try
		{
			if(src instanceof Button)
			{
				if(src == go)
				{
					AppletContext con = getAppletContext();
					site = new URL(getDocumentBase(), tf.getText());
					con.showDocument(site);
				}
				if(src == compute)
				{
					Compute();
				}
				if(src == clear)
				{
					clearAll();
				}
			}
			if(src instanceof TextField)
			{
				if(src == TF3)
				{
					Compute();
				}
			}
		}
		catch(NumberFormatException x)
		{
			TF5.setText("Listen! No letters Asshole");
		}
		catch(NegativeNumberException y)
		{
			TF5.setText("no negative numbers");
		}
		catch(DivideByZeroException z)
		{
			TF5.setText("You cannot enter zero");
		}
			catch(Exception e)
		{
			showStatus("the error is" + e);
		}
	}
}
class DivideByZeroException extends Exception
{
}
class NegativeNumberException extends Exception
{
}

<a href = "next.html">Do this next</a>