App flow question

[eluser]Evil Wizard[/eluser]
you could put a hook in to the script that switches tabs to submit the form, however that could lead to empty form submission and failed validation, resulting in false negatives. That said you could have a "is_dirty" check for the form, for instance when an input box changes, a checkbox/radio button is clicked and then in the tab change code check if the form state is dirty and submit the form but add the target of the tab change to the post data so the correct tab page is loaded on processing the form.

ADDED:
I would also suggest using JQuery to achieve this