[PHP-WIN] GD library for jpeg?

[Afan Pasalic]

I tried an example from php.net site:

<?php
header ("Content-type: image/png");
$im = @imagecreate (50, 100)
    or die ("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate ($im, 255, 255, 255);
$text_color = imagecolorallocate ($im, 233, 14, 91);
imagestring ($im, 1, 5, 5,  "A Simple Text String", $text_color);
imagepng ($im);
?>I'm getting some weird simbols/signs on screen (?PNG  
IHDR2d
t&nPLTE???é['ĖtL)But, when I try to use jpeg format - getting Fatal Error. 
Does it mean that my hosting company doesn't have instaled GD library that support 
jpeg?Thanks for any help.Afan