Simple Mesh Renderer

Hello I am kinda new to unity, only had it a few months so I am still trying to figure everything out. I want an object (A square or something easy) that is the child object of the FPS Prefab appear when I press something like P, and disappear when I press something like O. =/

I am not sure if this has been answered yet but I cant find any tutorials on it sorry =/

Set renderer.enabled to false in order to hide the object and then back to true to show it again.

oh wow D: I totally missed that in the reference manual Thanks =]