php password protect directory

Hi I am looking for away to password protect a website directory WITHOUT .htaccess or at least the standard .htaccess/htpasswd system
I have password protected sites before using sessions which work fine but require you to put the session code onto every page
I am wondering if there is away to "session proof" a directory with just one file that will auto-protect the whole folder and give functions like "log off"
I have tried googling it but have found nothing I want

See original post by saturn100