The Window class
The ui.Window class provides an interface to the window objects created
with the OPEN WINDOW instruction.
A window object is created with a form with the OPEN WINDOW WITH FORM
instruction, and can be manipulated with the ui.Window methods, after getting the
window object instance with ui.Window.getCurrent() or ui.Window.forName().
When the window contains a form, you can use the ui.Form class to manipule form element.