JS See if window is closed?

If I open a window with JS, is there any way to constantly check if it's closed again ? Or is it possible to send a message from the window I opened to the window that opened it saying it's going to close? I need to redirect a page as soon as it's popup closes!

Cheers!

There is no onclose event but their is an onUnload event.

found out I can open it as an object, and use myObject.Closed() which you return a boolean value, which is what I need. But I don't have access to the code that opens the popup and it opens it using OpenWindow(blabla), or something like that, without making it an object, so that's useless...

Cheers!