Once you have installed Vertical Toolbar on Firefox 4, immediately a vertical bar will be added at left side. This vertical bar holds bookmarks, download progress bar, print, and full screen mode buttons. You can add buttons to customize the bar. First change the extension’s configurations. To do this, right-click the vertical bar and select Vertical Toolbar Options. Now set the toolbar hiding behavior in both normal and full screen mode and define the bar placement. From Buttons pull-down menu, you can choose to show either icons or icons with text.