Help Please.. Labels jumping after button click/refresh

Hi. My JLabels seem to jump around after any button click or refresh. This was supposed to be a simple program. I have included the code since it is short. This is a simple program to calculate the interest on a loan. A text file called money.txt is needed to run the program. It should containt three numbers on the first three lines. Thanks for the help.


import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class Money extends JFrame implements ActionListener{
double currentTotal;
double interest;
double moneyOwed;
double interestPaid;
JButton makePayment;
JLabel label, label2;
public Money(){
super("Pay Me Back");
Container c = getContentPane();
c.setBackground(Color.orange);
setResizable(false);
setSize(520,200);
show();

try{

FileInputStream inStream = new FileInputStream("money.txt");
InputStreamReader read= new InputStreamReader(inStream);
BufferedReader reader= new BufferedReader(read);

String temp = reader.readLine();
Double d = new Double(temp);
currentTotal = d.doubleValue();
temp = reader.readLine();
d = new Double(temp);
moneyOwed=d.doubleValue();
temp = reader.readLine();
d = new Double(temp);
interestPaid=d.doubleValue();
reader.close();

makePayment = new JButton("Make Monthly Payment");
makePayment.setSize(175,30);
makePayment.setLocation(150,120);
makePayment.addActionListener(this);
c.add(makePayment);

// I have tried two labels and have combined them into one label, at least one is always jumping around.
// I have tried resizing and relocating after the button click.

label= new JLabel("Total amount owed: "+moneyOwed);
label.setSize(250,30);
label.setFont(new Font("Times Roman",2,15));
label.setLocation(150,10);
c.add(label);

label2= new JLabel("Total interest paid: "+interestPaid);
label2.setSize(250,30);
label2.setFont(new Font("Times Roman",2,15));
label2.setLocation(150,60);
c.add(label2);
c.repaint();
}catch(IOException e){
System.out.println(e);
}
}
public void actionPerformed(ActionEvent e){
//if(e.getSource()==makePayment){
String z = JOptionPane.showInputDialog(null,"Enter an amount: XXX.XX.","Make Payment",JOptionPane.PLAIN_MESSAGE);
if(z==null)
return;
Double d = new Double(z);
double payment=d.doubleValue();
try{
interest = currentTotal*(.03/12);
interest*=100;
interest=Math.ceil(interest);
interest/=100;
currentTotal += interest;
currentTotal*=100;
currentTotal=Math.ceil(currentTotal);
currentTotal/=100;
moneyOwed -= (payment-interest);
moneyOwed*=100;
moneyOwed=Math.ceil(moneyOwed);
moneyOwed/=100;
interestPaid+=interest;
interestPaid*=100;
interestPaid=Math.ceil(interestPaid);
interestPaid/=100;

label.setText("Total amount owed: "+moneyOwed); //resets the text for the two buttons to represent the new values
label2.setText("Total interest paid: "+interestPaid); // this is the only time, I reference these in the button click

File thisFile = new File("money.ben");
thisFile.delete();
FileOutputStream output = new FileOutputStream(thisFile);
PrintWriter printer = new PrintWriter(output);

printer.println(currentTotal);
printer.println(moneyOwed);
printer.println(interestPaid);
printer.close();


getContentPane().repaint();2
}catch(Exception a){System.out.println(a);}
}
public static void main(String[] args){
new Money();
}



}