dom.getFocus()

Availability	3.0
Description	Determines the part of the document that has focus.
Arguments	None.
Returns	One of the following strings:
	"head" if the HEAD area is active "body" if the BODY or NOFRAMES area is active "frameset" if a frameset or any of its frames is selected "none" if the focus is not in the document (for example, if it's in the Property inspector or another floating palette)
Enabler	None.