Interactively Scaling a 2D Texture

So I essentially am looking to scale the 2d image I'm using for my crosshair in a fps.

if(Input.GetKeyDown("e")){ crosshair.width += 5; crosshair.height += 5; }

that's pretty much it, I just want to push a button to enlarge my texture. Though that code doesn't seem to do anything at all.