<panel size='500' color='#00000080' padding='8' context='menu'>
    <label>@missing-content</label>
    <panel id='content_panel' size='480,100' color='#00000080' scrollable='true' max-length='400'>
        <!-- content is generated in script -->
    </panel>
    <button onclick='menu:back()'>@Back to Main Menu</button>
</panel>
