The first level of the widget hierarchy is the one just below the screen level, and is called level-0. You create a level-0 widget by not using the PARENT option to the ASSIGN command when you create the widget.
A level-0 widget is not constrained to be within another widget and may exist at any place within the HTBasic output window. The X and Y coordinates of the level-0 widget are relative to the upper-left corner of the HTBasic output window.
A level-0 widget has a title bar at the top and a resize border around it. You can assign most of the widgets to be level-0 widgets. (All dialogs are level-0.) Only level-0widgets can have a title bar on top of the widget, and a resize border around the widget. The title bar and resize border allow you to change the position and size of the widget.