1. click on or right click on an item, select "Add before", "Add after", "Add end" or "Add child " on the pop-up menu.
2. The Add new topics dialog will appear.
3. Set Item type as Link to existing HTML files. Set how to get topic title with Get title form drop-down list box.
4. Click on OK . After Select HTML files dialog appears, select the html files you want.
5. Click on Open. The html files selected will be add to Table of Contents.