Description of hotlink protection :
I wrote these functions to keep my GD generated images from being hotlinked. This was based on the idea that both the php script calling the image, and the image itself would have the same server time. If you try to use this script on a site that uses multiple servers, it would be a good idea to synchronize their cpu clocks. date_filter is to be used in the script calling the php resource you want to protect.
ASP
