The Navigation Window is the frame to the left of the program window. It allows
you to interact with the project. This is where you define the project units of
measure, variables, frequecies, outputs, substrates and 2-port data files used
by the project. It also shows a list of the project schematics and allows you
to select the schematic to be displayed in the right hand frame of the program
window.
Clicking on the arrow icons at the nodes of the tree allows you to expand or
collapse items. Right clicking on items will allow you to add, rename, modify
or delete items.