The image “http://zbulo.com/font/index.php” cannot be displayed, because it contains errors.

Trying to write something on an image. Andi.png and text.gdf exist (the font is php font). I don't know how, but I put this together on bits and pieces. Still no Idea on how to do it?

[php]
<?php
$imagedir="andi.png";
$font = imageloadfont('text.gdf');
$fontWidth = imagefontwidth($font);
$fontHeight = imagefontheight($font);
$text = 'HELLO WORLD!';
$fgColor = imagecolorallocate($imagedir, 0, 0, 255);
imagestring($imagedir, $font, 0, 0, $text, $fgColor);
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
?>[/php]