Get a random page from Homestuck web comic

HomestuckRandomImage.php

<?php
/*
Created by Ákos Nikházy
I use this in this app: http://ltats.nikhazy-dizajn.hu/

All Homestuck images are gifs numbered between 001901 and 009875 (to date). Sometimes the pages are flash animations or HTML5 games
*/
do 
{//do this while the random number is not an image

	$rand				= rand(1901,11000);//The first Homestuck page is 1901. At this point I am sure there will be less than 11000 pages of Homestuck
	
	$imageMaybe	= getimagesize('http://www.mspaintadventures.com/storyfiles/hs2/0'.$rand.'.gif'); //I test if its image by this
	
	$notImage		= (!is_array($imageMaybe))?true:false;
		
} 
while($notImage);
	
	$imageNumber = str_pad($rand, 5, "0", STR_PAD_LEFT); //we need this format: 001234
?>
<img src="http://www.mspaintadventures.com/storyfiles/hs2/<?php echo $imageNumber ?>.gif">