Gets the object that has the focus when the parent document has focus.
the element that has the focus.
You can set the active element with the setActive method or the focus method; however, using the setActive method has no effect on document focus. Use the focus method to cause an individual element to gain focus and become the active element.
The active element retains focus in the parent document even when focus is shifted from the parent to another application. If the focus returns to the parent document, focus also returns to the same active element.