imagettftext geeft FONT fout!!

<?php
// Set the content-type
header("Content-type: image/png");

// Create the image
$im = imagecreate(400, 30);

// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);

// The text to draw
$text = 'Testing...';
// Replace path by your own font path
$font = 'Arial_Black.ttf';

// Add some shadow to the text
imagettftext($im, 20, 0, 11, 21, $grey, $font, $text);

// Add the text
imagettftext($im, 20, 0, 10, 20, $black, $font, $text);

// Using imagepng() results in clearer text compared with imagejpeg()
imagepng($im);
imagedestroy($im);
?>

<?php
// Set the content-type
header("Content-type: image/png");
 
// Create the image
$im = imagecreate(400, 30);
 
// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);
 
// The text to draw
$text = 'Testing...';
// Replace path by your own font path
$font = 'Arial_Black.ttf';
 
// Add some shadow to the text
imagettftext($im, 20, 0, 11, 21, $grey, $font, $text);
 
// Add the text
imagettftext($im, 20, 0, 10, 20, $black, $font, $text);
 
// Using imagepng() results in clearer text compared with imagejpeg()
imagepng($im);
imagedestroy($im);
?>