Thanks, all . .
Mary, I look forward to hearing from you (but no rush, as I said, I'm away for a few days . . )
And Graham, I wouldn't flatter myself by claiming to be a software engineer (well, I could write a reasonable FORTRAM programme 25 years ago, and my 6502 Assembler's not bad, but these days that hardly qualifies . . )
Cheers - you folk don't know how comforting you all are!
George