How do I make arms physically animated ?

Hi everybody !

I've got a little problem, i want to make animated arms with physics propriety. I find some tutorials, i try during hours, but there is something wich doesn't work and i don't know what it is...i just want that the arms follows the mouse and move in consequence...

Here's my caps, if you could help me it will be very cool...

dropbox.com/s/5a9cf7vhxbsilpf/arms2.capx