Rollis13 and Rory,
Thank you both for your help. My saving problem has been resolved and now works on both Mac and Windows. I have incorporated your suggested code as it's much tighter than my original, although the problem was actually a silly error on my part! I had included a number of "/" in the reference that was making up the filename, which works on a Mac but is not accepted in Windows!
Many Thanks,
Woz.