Navigator 2.0, Internet Explorer 3.0
The top property is a read-only reference to the Window object that is the top-level window that contains window. If window is a top-level window itself, then the top property simply contains a reference to window. If window is a frame, then the top property contains a reference to the top-level window that contains the frame. Note that the top property refers to a top-level window even if window refers to a frame contained within another frame (which may itself be contained within a frame, and so on). Compare this with the Window.parent property.
top.defaultStatus = 'Welcome to my Home Page!';