Get the current size of the application window, excluding the size of the title bar and borders (this is the 'client' area).
First available in version 3.0 build 2039.
width - Width of the client window in pixels
height - Height of the client window in pixels
When this method is called synchronously, a return object containing the output parameters is returned to the caller immediately.
var return_obj = ssCore.Win.getClientSize();