Thanks for that. Did get it to work, just trying to make it difficult for myself!
My initial problem was trying to register the variable, and then trying to use it as an array. Don't! Just create the array, THEN register it.
Why was I doing this? 'Cos I'd picked up another bit of code someplace which said it was a good idea to check/set your session variables at the top of each page - but as I say if you do this you cannout then use your registered variable as an array (only as a char, int, etc..)
James