Craig

I think I'm beginning to get to grips with it.

The UI Tier will only action methods in the Custom Business Object (BO), then the BO will do all the necessary processing, all the form needs to know is if it was successful or not, keeping the UI to do what it's there for - action user commands.

The BO will then deal with the Data itself, so that no matter where you put your BO ( I'm beginning to dislike those letters!!!), it will always validate or whatever correctly ,because it is contained in that Object.

Am I right in asuming that, i want to be clear before I start venturing down this path.

Thanks
Kev