A reference to the parent of the current window or subframe.
If a window does not have a parent, its parent property is a reference to itself.
When a window is loaded in an <iframe>, <object>, or <frame>, its parent is the window with the element embedding the window.
Syntax
parentWindow = window.parent;
Example
if (window.parent != window.top) {
// we're deeper than one down
}
Specification
See also
window.frameElementreturns the specific element (such as<iframe>) thewindowis embedded into.window.topreturns a reference to the top-level window.