how to re-init X for new monitor?

[Patrick O'Callaghan]

On Thu, 2008-04-03 at 11:25 -1000, Dave Burns wrote:
> I set up FC8 using one monitor, now want to put it in use with
> another. Only the upper left 75% of the new screen gets used. How do I
> tell fc8 or X, whichever, "there's a new screen, reinitialize
> yourself!"
> Dave

system-config-display.

poc