On the left side of the Helptrix Author window is table of content. ToC shows whole book in form of hierarchical tree structure. At very top of tree is the tree root - book. Book may have several chapters, also displayed as books. Chapters may include chapters or topics. Topics are represented as paper sheets: blue if the topic is locked and red if the topic is not locked.

Figure 2.11. Book ToC

All changes to the book structure takes place here. When you click the right button on the mouse, popup menu appears and via this menu is possible to insert new chapters and topics, delete them or change their properties. Another possibility is to reorganize existing chapters and topics by drag'n'drop method. It is possible to drag'n'drop topics and chapters to new destination and that way change the book structure.