using onbeforeunload event, url change on selecting stay on this page

Question

Rewriting the question -

I am trying to make a page on which if user leave the page (either to other link/website or closing window/tab) I want to show the on

Answer 1

It's better to Check it local.
Check out the comments and try this: LIVE DEMO

var linkClick=false; 
document.onclick = function(e)
{
    linkClick = true;
    var elemntTagName = e.target.tagName;
    if(elemntTagName=='A')
    {
        e.target.getAttribute("href");
        if(!confirm('Are your sure you want to leave?'))
        {
           window.location.href = "http://google.com";
           console.log("http://google.com");
        }
        else
        {
            window.location.href = e.target.getAttribute("href");
            console.log(e.target.getAttribute("href"));
        }
        return false;
    }
}
function OnBeforeUnLoad () 
{
    return "Are you sure?";
    linkClick=false; 
    window.location.href = "http://google.com";
    console.log("http://google.com");
}

And change your html code to this:

    try it