It is not a rocket science to pass objects from child window (popup) to main window. The problem I encountered today was IE and passing complex objects. So it is just an IE issue as far as I know. The problem occurs when you pass some object (not a simple String or Number) to main window: window.opener.takeAnObjectFromChild = { title: "Should even be available when I close the child" }; and you then close the child window, next time the main window tries to access the passed object:

In javascript, if we copy objects or their properties, the reference still remains and by changing the new object the old one is changed, too. To clone or do a clean copy of an object I found a very useful solution by Jan Turoň on StackOverflow: Object.prototype.clone = function() { if(this.cloneNode) return this.cloneNode(true); var copy = this instanceof Array ? \[\] : {}; for(var attr in this) { if(typeof this\[attr\] == "function" || this\[attr\]==null || !