Sorry about that Bear. Actually we have a page which will unsubscribe users from newsletter. It has a link close window. Which should close browser window.
This close the browser window on IE. If I use below function. This close browser window on chrome. But not on firefox. So I was looking for an alternative which will work on all the browsers. Thanks and I hope now its clear.
Using hacks will never be cross-browser safe. You can only close a window that you opened yourself. Anything else is not allowed, and is very very rude. You should not be trying to close the main browser window. Please read InterfaceDesignersRule1