Once you have a new Window Layout script open in an editor, you can edit that script's window. To edit the window, go to the Resources page, move the mouse pointer over the word "(default)" under "Windows", and double-click the left mouse button.

This will present an empty window with a title (ie, caption) of "Window Title". This is our script's window to which we'll be adding controls and other resources.

You'll also see a small window labeled "Toolbox". This is discussed later.

Note: If the Toolbox window is on top of the window being designed, you can move the Toolbox (with the mouse) to some other area of the screen.