Deany

Sharing is cool, thanks for doing it! found some problems however that you should fix up... i wont get to nit picky (i can get be a perfectionist at times!)
 
ok so 2 code improvments:
 
1) when checking vars use if (isset($_SESSION['autherised'])) { }
2) dont use $_SERVER['PHP_SELF'] as an attacker can play with it __FILE__ will give you the same result
 
and a major security issue, granted its not the easiest thing todo but i could by-pass your login system and anyone with access to your router could do so with not much hassle at all! especially if the attacker is motivated to destroy your world... humans can be very resourceful!
 
Allowing people in just from the IP used is I'm sorry to say stupid... not so bad if the script is to be only used by you... but it ain't secure thats for sure I would flat out remove that bit or change it so the session is bound to the IP (not so good for people on very managed ISP's but hey) but you would have to actually login to get authed in the first place.
 
It's great seeing people post scripts, keep it up