File Association

[John]

Hi, All

I am new here, and to kubuntu, I have set up kUBUNTU 10.10 on my laptop
(Extensa 5630Z), everything is going well, there is however a small
problem with Thunderbird, and Firefox in that when I click a link in a
file or from the desktop then Thunderbird fires up instead of Firefox ??

I decided to do a test by creating a "link to Location" on the desktop,
called it test linked to "http://www.google.co.uk", when I clicked the
link Thunderbird fired up together with a pop-up to set a program as the
default (I thought woopeee! its sorting itself out) I selected
/usr/bin/firefox and ticked the check box to make it permanent, shut
Thunderbird down and tried again, now I get both Thunderbird and Firefox
starting up, so a little progress.

Now where do I remove the association for Thunderbird to stop it
Starting up in the above situation ?

I have Googled and and found nothing of help.

All help much appreciated

-- 
Best Regards
John