The main Active Call Center program window has a menu bar that stretches across the top of the window.
The center portion of the window shows the open Call Tree (if any). All Call Trees start with the Answer_Phone Node: it is shown at the top of the Call Tree window with a telephone icon next to it. Question Nodes are shown with question marks; Action Nodes are shown with lightning bolts.

For more details about Call Trees, refer to the chapter on Call Trees.