Javascript window close event rather than unload event for all browsers

I want to alert a user while the user tries to close the browser with out siginingoff or without saving some settings.

I am ding unload option in another page to alert unload data, but how can i alert a user on window.close(its not taking)

window.onbeforeunload = confirmExit;
function confirmExit(){
    if(开发者_Python百科readCookie("onlineVD") == "playing" && Confirm_Delete=="0")
    {
        return "You are leaving a video which is in play mode.Are you sure want to exit this page?";
    }
    else{
        Confirm_Delete="0";
    }
}

I want window.close for on tab close and on window close in all browsers.

Please find me a solution

The event code you have already seems to work when I test it. You just need to return false to stop the browser from closing. The user will be asked if they're sure they want to navigate away from the page.

I'm using this shortened version of your code:

window.onbeforeunload = confirmExit;
function confirmExit(){
    alert("confirm exit is being called");
    return false;
}

The Mozilla documentation indicates that you should set the event.returnValue instead of simply returning a string:

window.onbeforeunload = confirmExit;
function confirmExit(e){
    if(readCookie("onlineVD") == "playing" && Confirm_Delete=="0")
    {
        var msg = "You are leaving a video which is in play mode.Are you sure want to exit this page?";
        if (e) {
            e.returnValue = msg;
        }

        return msg;
    }
    else{
        Confirm_Delete="0";
    }
}