How to drop a button on my FF toolbar when it's core it's click and not the disclosure triangle

I have a button on my toolbar

When I click the right disclosure triangle it drops-down with it's contents. I want this to happen also when I click the core of the button, which cu开发者_Python百科rrently does nothing.

How do I enable this functionality on the button?

It looks to me as if you're using <toolbarbutton type="menu-button">. This creates the separate core button element. What you probably want is a simple <toolbarbutton type="menu">.