I'm learning how to build a Oracle Portal in Oracle9iAS.
Teh problem I have encounterd is how to make an interaction between two portlets
in a region.
For example :

1 portlet has a button. When I push this button the second portlet
has to show up beneath the first portlet.

Also I would like to know if it's possible to use business objects with Portal.
The meaning is to draw a diagram in a portlet, using the data from a database.