Returns a Positioned Element consisting of two elements
placed in the same position. To be able to see the lower (main)
element you must either call hide()
on the overlay,
or make it transparent with CSS.
The element containing both elements.
HTMLElement
The higher element. Any
getData()
or setData()
call on the
returned element will not be passed on to this overlay element.
toolkit.HTMLPositionedElement
The lower element.