Writing to a txt file... without overwriting

ok people…

How can i write to a txt file without overwriting the existing data instead making go to a new line?

my current code to write to a txt file is:


<?php

$myFile = "test.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = $_GET['text'] . "-" . $_GET['name'];
fwrite($fh, $stringData);
fclose($fh);

?>

Anyone know?