The default CSS class is "button".
Non-xul extension: Toolbarbutton supports Toolbarbutton.getHref . If Toolbarbutton.getHref is not null, the onClick handler is ignored and this element is degenerated to HTML's A tag. author: tomyeh
Default: null.
Default: "normal".
Default: null. If null, the button has no function unless you specify the onClick handler.
Default: "horizontal".
Default: -1 (means the same as browser's default).
Note: it is useful only if href ( Toolbarbutton.setHref ) is specified (i.e., use the onClick listener).
Default: false. since: 3.0.1