a PHP script to create PDF from any URL.

I want a PHP script or set of scripts which can convert any URL to PDF file and save it on the server or download it. All the files made will have to be hosted on my server. The script should take 1. URL 2. Paper Size (A4 or letter or legal) 3. whether to download or save (in case of save it must give a link ( tag) to the saved file) as input and generate PDF. Please bid quick as I need it done ASAP.