Focus on popup-windows

[Jesper Holmberg <jesper holmberg 5791 student uu se>]

I have a problem where popup-windows (transients?) don't get the input
focus when they show up. Say for example that I have Opera running on
desktop1, and then work in an xterm on desktop2, so that I am looking at
desktop2. If an error occurs in Opera, it opens up a dialog about the
error on my desktop2, but the focus is still in the xterm, so that when I
type something, the input is shown in the xterm window. I would like
windows that pop up like this to get the input focus, is this posisble?

TIA,

Jesper