<?php
header('Cache-control: public, must-revalidate, max-age=3600');
$im=imagecreate(100,30);
$bg=imagecolorallocate($im,255,255,255);
$textcolor=imagecolorallocate($im,0,0,255);
imagestring($im,5,0,0,date('U'),$textcolor);
header('Content-type: image/png');
imagepng($im);
?>