I have been following the tutorial to create buttons, when it said create a func_button entity I could not find it in the entity list. Apon further study at http://www.hl2world.com/wiki/index.php/Category:Entities I found out that I am missing most of the func_ entities from my entity list (see screenshot), can someone tell me why, do I need to download them seperatly or is anyone else having this problem? I tried searching the forums for missing entity and missing func_button but came up with no results. Could anyone give me some help it would be appreachiated.
www.encore-games.com/images/func.gif (screenshot)


