Join button then add to list

Is it possible to have a web app on a server (static ip) and have it so when you click join it adds the persons name and ip if possible to a list( ip is optional) its for a game. so i want want people to join then t adds there name to a list/ how cani do that?

you'd need some sort of database integration or you could just use flat files...

can you giveme a example cuz im totaly a newbi to php

http://www.php.net/manual/en/ref.filesystem.php