Simple example of expiring download pages?

Hi, I'm building a very simple online store and I need expiring download pages for people to download the items they purchased. Surprisingly, I couldn't find an example of this code online. I know how to do it in Lasso, and it's quite easy. You just search the database against download attempts or expiration time/date, and if it succeeds, return this (it's Lasso code but you get the idea): [Output_None] [Var: 'file' = (Include_Raw: 'pathname/sourcefile.zip')] [Var: 'filename' = 'product.pdf'] [Var: 'content_type' = 'application/pdf'] [Header] HTTP/1.0 200 OK Server: Lasso/6.0 Content-Type: [$content_type] Content-Length: [$file->Length] Content-Disposition: attachment; filename="[$filename]" [/Header] [/Output_None][$file] Can anyone suggest the PHP code for this?