Displaying PDF file

I've made a website for a real estate appraiser, who wants to put all his appraisals for his clients online. I have stored these PDF documents in a folder outside of the webserver folder, for security. When a client successfully logs in and clicks the link to biew the PDF, I have a PHP script that does the following: <? Header("Content-type: application/pdf"); include("../pdfs/whatever.pdf"); ?> It worked great at first, and still does with some PDF documents. With others, it gives says something like... Parse error: parse error in /path/to/pdfs/whatever.pdf on line 410 Why does it work with some PDF docs, and not others? Is there a better way to display PDF files (without putting them in a web-accessible folder)? Thanks, Joseph