To create a new screen design file (extension: .uff), click on the menu icon 
(+ button). Once the file is created, it is added to the screen definition list.
After adding the file, change the screen name in the [Object] pane of the Properties area = [Basic Info] tab = [Name].
If necessary, you can use the menu icon 
（Click (Save) to save the screen color, size, and information on each control placed on the screen in a screen design file (the same can be done by selecting [File] ⇒ [Save Selected File] from the TOP menu).
Also, 
(Save All) will save all modified files, including the screen design file (the same applies if you select [File] ⇒ [Save All] from the TOP menu).
