Darrel

Thank you very much. I have taken a look and 'instantly' it doesn't look so easy to understand, however it also appears to be very crafty and very useful. I am going to plug away at your code until it IS understood and then add this new-found knowledge to the ever increasing store of accumulated wisdom from all of you experts.

Many thanks again to you for enlightening me and of course to Skimask for his valuable input

Adrian