[O] conditionally includes or file options

[Jason Lewis]

Hi,

I have an org file stored on a Dropbox drive. I need some file options
in it for exporting to reveal.js using ox-reveal. eg:

on my mac:
#+REVEAL_EXTRA_CSS:
file:///Users/jason/source/reveal.js-fullscreen-img/fullscreen-img.css

on my windows computer:
#+REVEAL_EXTRA_CSS:
file:///C:\Users\jason\source\reveal.js-fullscreen-img\fullscreen-img.css


I'm alternating between a Windows computer and a mac for writing this
document, and so the path is different.

Is there some way I can conditionally set the path based on the computer
I'm exporting it on?

Thanks,

Jason

-- 
Jason Lewis
http://emacstragic.net