Oracle Forms

I am working on a form say 'A'. In this form, I have a tabbed canvas 'B' with 4 tabs.

I created another stacked canvas 'C' on which there are elements from 3 different blocks. Now I need to make this stacked canvas as an element of tab2 in canvas 'B'. I.e., if the user clicks on the tab2 of canvasB, it should show the stacked canvas C below the tab.

How can I do this?

Thanks,
Chiru