callFunction changes

re-add local scope for __desc
correct parameter order for call to rp_callFunction

I was assuming the local scope of __desc was removed by accident - It's not too important, but I assumed it wasn't needed outside of the function. perhaps we should have a document btw to lock down some styles/naming - like with __ in variable names. should we use for all, or just global or ?

Other fix is the one I mentioned in the code comment, with parameter ordering being changed, this call needed switching round.

Cheers.