Thanks for the compliment Fred. Around here it appears that the attitude is that we like to help those who are trying to help themselves. I like that attitude. You did a fair amount of the ground work and got stuck. I realised that I may be able to help so I did. Others have done the same for me. No doubt you will help someone else too given the opportunity (or, indeed, may have already done so).

Note to other posters to this forum and who didn't get a response: consider whether you just posted a "I want to do this. How do you do it?" question. Fred already had his solution up and running and just needed a hand. That's the way we roll ;-P