How to SAVE new instructions added to the Firefox user preferences file?

[Karl Klinger]

Bas Roufs wrote:
> Dear Everybody
> 
> At present, I am trying to save a few added instructions to this file:
> /home/bas/.mozilla/firefox/a1ooj68h.default/prefs.js
> It is the file which contains the user preferences for Firefox 3.05 at
> Kubuntu  8.10.
> Via Kate, I try to add some instructions meant to instruct Firefox to
> allow to use the 'Rich Text editing demo' functionality at a specific
> website - in my case a site via which I am working at the website for
> a client. That's why, I have opened a few times the above mentioned
> prefs.js file with Kate and pasted to it some instructions copied from
> this site: http://www.mozilla.org/editor/midasdemo/securityprefs.html
> While doing so, I also took into account special Linux/ Unix
> instructions from this site:
> http://www.mozilla.org/unix/customizing.html#prefs
> 
The instructions say to paste the lines into user.js, not prefs.js.

Karl