Partially disable checkbox

[Greg Breland <gbreland mozillanews org>]

I need to partially disable a checkbox control.  I don't want the
checkbox to toggle when a user clicks on it but I want the "click" event
or something similar to fire.  Something similar to the "editable"
property on a text control.

I've thought about using the click event to just toggle the control
back, but figured there was probably a better solution since this would
cause a lot of complications for my program.

I need to do this because I creating a simple form design app and when
the user clicks on a control the properties for that control are
displayed in another panel, but I don't want to the checkbox to toggle. 
If I toggle the checkbox back in the "click" event then I have to have a
way to know that that "click" event was user based and not done by the
user setting the state property via the control panel.