Marking Elements

To mark elements of the current variable user interface:

To mark one element, open the Selection menu and select the element.
The selected element is marked (with handles). All other elements are no longer marked.
or
Mark elements by clicking them:
When you click one element, the marks of all other elements are canceled.
To mark more than one element, press and hold the Shift or Ctrl key while you click an element. The element is marked. The marks of the other elements remain.
To cancel a marked element, press and hold the Shift or Ctrl key while you click the element again.
or
Mark the elements by dragging a frame:
1. Click a free area of the window.
2. Keep the mouse button pressed and drag a frame with the mouse.
3. Release the mouse button.
  All elements within the frame are now marked. The marks of all other elements are canceled.