help downloading image files

[sqwit]

below is the code i'm trying to use to download image files:

<?php
header("Content-Type: application/save");
header("Content-Transfer-Encoding: binary");
header("Content-Disposition: attachment; filename=$down");
header("Content-Length: $size");
readfile("$down","r");
?>

it seems to work for text files but it saves empty image files. any ideas what i'm doing wrong or missing?

[hand]

<?php 
$size = filesize($down); 
header("Content-Type: application/save"); 
header("Content-Transfer-Encoding: binary"); 
header("Content-Disposition: attachment; filename=$down"); 
header("Content-Length: $size"); 
readfile("$down","r"); 
?> 

or

<?php 
header("Content-Type: application/save"); 
header("Content-Transfer-Encoding: binary"); 
header("Content-Disposition: attachment; filename=$down"); 
readfile("$down","r"); 
?>