editing maxforwardspeed in charactermotor via script? help!

hey guys I’m trying to create two variables, a run speed and a walk speed but no matter how I do it, it doesn’t work. can anyone give me some help? I’m using the fps controller prefab if that helps.

thanks.

If you want to implement run speed in the First Person Controller (and crouch too!), take a look at my answer in this question: How to Make the FPS Character Controller RUN and CROUCH - Unity Answers