PHP schedule check through a PDF

I need a PHP file that will check for differences in a PDF file every 30 min, i need you to make it downloade this PDF file with a schedule. [login to view URL] On the site it must be possible for people to sign up, they signup with a email and a page number in the PDF. Now that they have registered, the site should check for differences on that page, and if there is a difference, then you should get a email with a link to my page with a picture of the new schedule And that page you see the new schedule, should look nice, not just a white screen with a picture :) Please write to me what you are going to do, so i now that we understand each other :)