Chromeless and disabling app error windows

[M]

Is there a way in Chromeless to disable error windows shown by gecko?

For example, if there is a cert problem, I would rather have something logged into a log then pop up a "Secure Connection Failed" window.

I am playing with a simple non-interactive kiosk app and the errors are very hard to get rid of (no input device) and very ugly. I want to disable any popups, be they from the js or app itself.

Thanks,