Campanilla - I had come up with skylight but didn't make sense - many thanks for resolving this for me. I think thats my last one so hopefully my form will be in the post tomorrow. Although you try your best to answer as many questions as you are able it is nice to know that there are people on this site that are happy to give you a hint or a nudge in the right direction.
I hope I can in the future help others.
Thanks again for your help.