Z-Index issue

[Stephen McCrea]

I have a .aspx page that contains a drop-down list box, among other things
and I want to overlay a panel that contains an error message and a button
that hides the overlaid panel.

The panel (with highest z-index) covers all other items on the page
(buttons, labels, etc...) but not the list box. I have tried to make the box
non visible before showing the overlay panel, which works; but I can't get
the listbox back by making is visible again (Visible = true).

Am I missing something?

Thank you,