Add a bool to animator & activate by key press

Hey guys,

i want to know i can add a bool via script to my animator and how i can change this bool by pressing “E” on my Keyboard to true/false.

so in general: I want that the “Character Attack” Animation is playing once when i press “E” on my kexboard.

http://unity3d.com/learn/tutorials/modules/beginner/animation/animator-scripting