How would I change a character's movement speed based on how far I tilt the joystick?

The title basically says it all. I have a character set up with basic movement with my controller’s joystick. The problem is I want to switch from a walk when the joystick is slightly tilted to a run when the joystick is pushed all the way. I’ve done some looking around but I can’t quite seem to find exactly what I’m looking for. Any help is greatly appreciated. Thanks!

so basicly what you will need is,
var startposition = 0;
var positionnow = position.//what ever for joystick;

so then where ever you set up your speed put positionnow, now the really tricky part is finding what unity reads the joysticks movement as, it might simply read it as mouse position, but i will look into it more later.

also see http://wiki.etc.cmu.edu/unity3d/index.php/Joystick/Controller

and then i read there is some joystick controls in mobile assets?

This is one of the most basic things that pretty much every movement tutorial goes over. The fact it’s a PS3 controller changes nothing.