Download a pdf file using link

<!-- index.php -->
<a href="http://your_site_name.com/download.php?file=AENSWineRegBrochure2012.pdf">Click here to download PDF</a>

<!-- download.php -->
<?php
header('Content-disposition: attachment; filename=file_name.pdf');
header('Content-type: application/pdf');
readfile('images/file_name.pdf');
?>