I was wondering why my codes works fine in chrome but it won't work in IE. I believe object.onunload works in IE too.
function showPopup() {
myPopup = window.open("", "", "dialogWidth:500px;dialogHeight:500px");
myPopup.onunload = function() {
alert("Your popup has been closed.");
}
}
<a href="javascript:showPopup();">Click me for popup</a>