Why is the DOF check box in BGE gray? I know there may be a very simple answer, but I'm still kinda new at Blender's Game Engine and was wondering if I don't have something checked in the "addons" area that will enable the DOF check box on the side panel (Opens using the "N" key, to help with my description, lol). It's under the "shading" tab. 

Like I said it may seem very simple, but I'm a NOOB, lol. So any help will be greatly accepted. Thanks :)
Actually I figured it out, lol. But just in case someone had the same problem I had... To get the checkbox to become un-grayed (Or make it usable, lol) You must be in "Camera View". Otherwise it will remain gray. I hope this helps someone not experienced enough in Blender. Happy Creating :)