they have nothing to do with Javascript, these stuffs are part of Dynamic HTML, see details at (IE) http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/dhtmlrefs.asp
karma(无为)老兄,what kind of software do u use to write Javascript?notepad?
yes, I use notepad most of the time, but use visual interdev occasionally
http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/dhtmlrefs.asp
http://www.microsoft.com/china/scripting/