Call to undefined function imageloadfont() ?

hello i have script from php.net but not works
also can i install GD from cpanel? please how?

  <?php
// Create a new image instance
$im = imagecreatetruecolor(50, 20);
$black = imagecolorallocate($im, 0, 0, 0);
$white = imagecolorallocate($im, 255, 255, 255);

// Make the background white
imagefilledrectangle($im, 0, 0, 49, 19, $white);

// Load the gd font and write 'Hello'
$font = imageloadfont('./04b.gdf');
imagestring($im, $font, 0, 0, 'Hello', $black);

// Output to browser
header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>       

PHP:

 

Contact your host.

 

Yeah ask your hosting provider and check if GD library is configure proper.

Cheers