Check if a popup window is already open before opening it using Jquery

Question

I want to check if a popup window is already open , before I open the popup window. How do I get it done using Jquery?

Below is my code to open a new popup window :

Answer 1

var popup;
function openPopupOneAtATime() {
    if (popup && !popup.closed) {
       popup.focus();
       /* or do something else, e.g. close the popup or alert a warning */
    }
    else {
       popup = window.open(...);      
    }
}