Problém s tiskem

<?php
$dvereFilename = "http://svestkaeurookna.cz/designer/dvere.png";
$oknaFilename = "http://svestkaeurookna.cz/designer/zarubne/zaruben-1.png";
$klikaFilename = "http://svestkaeurookna.cz/designer/kovani/left/hgu-a.png";

$w = 158;
$h = 306;

$dvere = imagecreatefrompng($dvereFilename);
$okna = imagecreatefrompng($oknaFilename);
$klika = imagecreatefrompng($klikaFilename);

$matter = imagecreatetruecolor($w, $h);
$brown = imagecolorallocate($matter, 102, 0, 0);
imagefill($matter, 0, 0, $brown);

imagecopy($matter, $dvere, 0, 0, 0, 0, $w, $h);
imagecopy($matter, $okna, 0, 0, 0, 0, $w, $h);
imagecopy($matter, $klika, 0, 0, 0, 0, $w, $h);

header('Content-Type: image/png');
imagepng($matter);