Design Question

[psinyc]

here's a design question or two:

1) let say i have a a hierarcy of user controls for a nav
bar. The first one is a general bar (reports,
applications, info center, faq, etc), and the second bar
(which is also a user control) would be launched on a user
click from the first bar. Can I change the calling bar to
the called bar (both user controls) in the <td> of that
table?

2) what type of content can be placed in user control vs a
panel, and what is recommended or easier to work with? can
datagrids, ie, html, other application be loaded into
both, depending on a specific event?

thanks all,
psinyc