<afx-app-window apptitle="Booklet" width="600" height="500" data-id="Booklet">
    <afx-hbox >
        <afx-tree-view data-id = "toc-ui"  data-width="200" dragndrop="true"></afx-tree-view>
        <afx-resizer data-width="3"></afx-resizer>
         <div data-id = "mycontainer">
            <textarea data-id="markarea" ></textarea>
        </div>
    </afx-hbox>
</afx-app-window>