Hi Elisabeth,
If you're still using tkgui.addMenu, that returns a Tkinter.Menu instance.  You add an item to the menu with:

menu.add_command(label="menu item name", command=myFunc)

which will cause myFunc to get called (with no arguments) when that menu item is selected.  There's a lot of documentation available for the Tkinter.Menu class, just Google "Tkinter menu".   I personally use:

http://infohost.nmt.edu/tcc/help/pubs/tkinter/

but that may or may not be overkill for your purposes.  Also, Chimera's tkgui._createMenus function shows a lot of uses of Tkinter.Menu instances.

--Eric

                        Eric Pettersen
                        UCSF Computer Graphics Lab
                        http://www.cgl.ucsf.edu

On Jan 24, 2011, at 10:40 AM, Elisabeth Ortega wrote:

Dear Chimera Dev Team,

I created a new item in the menu bar but my question now is how can I put options in the new bar? As you know, to put any option in the menu 'Tools' we "only" have to copy the new folder in chimera/share/ . I'm trying to do the same with my new item but the only way that I found to do so is modifying the ChimeraExtension.py file of VolumeMenu. Exists any other possibility much easier than that?