Hilmar, thank you very much for your specific & detailed explanation, which was
very kind of you, and must most enlightening for me.

I thank Evan and Dan also, for their extended explanations, which was very useful. I am sure, to you computer gurus this is a part of your every day life, but unfortunately not so for me.....! I periodically face a blank wall which I believe could be rather complex to scale,so I keep walking around it....to reach my destination, not realising that the door to pass through has not even been noticed along the way!

Nice to have good friends in UT! Cheers!

Thanks again.

Regards,

Steve.