Mozilla Firefox 1.5+
Mozilla Thunderbird 2.0+
Mozilla Sunbird 0.8-0.9 / Calendar 1.0pre
To add new button you should:
* Go into menu View -> Add new Button....
* Fill in the fields Name and Code.
(You can leave the field Image empty. Then the button will have a standart image).
* The Initialization code executes once a time when the browser startups, and at any time a custom button was recreated, i. e. edited or dragged from "Customize Toolbar" dialog. You can leave it empty too.
* Go into menu View -> Toolbars -> Customize... , find new button and drag it to any toolbar.
The extension adds to Firefox a "custombutton" protocol, that allows to install buttons from web-pages.
Discussion (both in English and Russian):
Discussion (in Russian): http://forum.mozilla-russia.org/viewtopic.php?id=9591
If you have found a bug, don't complain here, but try to explain it here http://sourceforge.net/p/custombuttons/tickets if you want to have it fixed