Toggling the Focus of the Split Window
Press the F6 function key on your keyboard to toggle the focus in your window. The pane with the flashing cursor has the focus. Any actions you perform affect the pane with the focus. Pressing F6 passes the focus to the other pane.
If you have the Arbortext EditorCommand line visible at the bottom of the Arbortext Editor window and a split window, pressing F6 repeatedly passes the focus counterclockwise between the two panes of the window and the Command line.