HELP - Animations not playing in Game

Hello,

I am very new to using Blender
I created some animations for a rigged humanoid model that i found (walking, running etc) and set one of them to play when pressing a button via the Logic Bricks. But when i test the game it doesn’t play… In the video tutorials that i followed, it was working fine, so i’m doing something wrong. Please help, i’m stuck… You can find the blend file at the following link:

http://www.mediafire.com/download/f0xbf516begk05b/My%20Game.blend

Any help would be greatly appreciated