The <menubar></menubar> defines menu bar which can be placed
as any other screen elements. In the menubar widget you have to create
menus with the <menu></menu> tag, and inside the menu
must be at least one menu item created by the
<menuitem></menuitem> tag.
The next example shows how to create a simple menubar with only one menu:
<menubar>
<menu>
<menuitem>
<label>gtk-open</label>
</menuitem>
<menuitem>
<label>gtk-save</label>
</menuitem>
<menuitem>
<label>gtk-quit</label>
<action>EXIT="quit"</action>
</menuitem>
<label>File</label>
</menu>
</menubar>