top
Summary
Retrieves the topmost ancestor window.
Property of dom/Windowdom/Window
Syntax
var topwindow = window.top;
window.top = value;
Return Value
Returns an object of type DOM NodeDOM Node
Examples
var topwindow=window.top;
Usage
This property is especially useful when you are dealing with a window that is in a subframe of a parent or parents, and you want to get to the top-level frameset.
Syntax
Attributions
Mozilla Developer Network : [top Article]
Microsoft Developer Network: [top Property Article]