How to Add Button Icon in Plugin?

[aldspamacct]

Greetings,

I'm trying to learn/understand how one adds an icon to a Plugin Button.  I've installed a few 3rd party plugins and some have an icon, others don't.  I've spent some time looking through the source but an not seeing where one would include an icon next to the button text.  Would someone be kind enough to point me in the write direction?

Thank you all!

td

[SKaero]

Well first of all where do you want to add the button?

[aldspamacct]

I would like to start with Preferences->Section, that is the right Panel.  But I would have the same question if adding one to the left Panel.  Other than this primer (http://trac.roundcube.net/wiki/Doc_Plugins) to writing a plugin, are there any other resources, tutorials on the subject?  This information simply covers the bare basics.

Thank you

[SKaero]

The icons for those spots are add/changed via css.