How To Set An Auto Playlist According To A Folder On Wmp 12

I am running Windows 7 SP1 and using windows media player 12.I keep all my music folders and files in a main folder that i have named it : Music.I want to create an auto playlist in windows media player 12,so that any changes in the Music folder on my hard disc, including adding or deleting songs and aslo changing the tags, be automatically set in that playlist.I remember this feature in wmp 11 but don t know how to do it in version 12.