Appending New Lines In A File

I have this part of the file.

class CreateFile implements ActionListener{ // MailOrderCreateFile.java
@Override
public void actionPerformed(ActionEvent ae){
String getDestination = txtDestination.getText();
file = new File(getDestination); // needed for Creating and Displaying the file
currentTime = txtCurrentTime.getText();
try {
FileWriter fw = new FileWriter(file);

[Code]...

What I wanted to do is that every time I press the button that will activate this part of the code, it will write to a .txt file defined in my txtDestination var (a JTextField). After the first time the file was created, it must append a new line every succeeding presses. However, everytime I do this, it just simply overwrites the contents of the .txt file. The example output would have been like this:

First time.

O R D E R D E T A I L S:
Time ordered: 01/21/2015 Wed 10:21:54 PM
Item number: 10
Item price: $4.59
Quantity ordered: 12,321
Total: $56,553.39

[Code]...

I've tried createDetails.write but to no avail.