Detect if new window if opend using javascript
<p>Creating a small chat application where user can start chat by clicking on chat button next to user's profile.</p>

<p>Once anyone will click on chat button a popup window will appear. Now I want to detect dynamically if this popus is still open or closed. </p>

<p>If popup is opened= Display new message alert in notification.</p>

<p>if popup is closed = Do not alert new message in notification (As chat window is already opened)</p>

<p>This is what I tried:</p>

<pre><code>    &lt;a href="#" onclick="popitup("http://domain.com/chat/2")"&gt;Chat with user 2&lt;/a&gt;
    &lt;a href="#" onclick="popitup("http://domain.com/chat/1")"&gt;Chat with user 1&lt;/a&gt;
</code></pre>

<pre class="lang-js prettyprint-override"><code>// on document ready
setInterval(function(){
    chkAlerts();
}, 10000);

var newwindow = null;

function popitup(url) {
    if ((newwindow == null) || (newwindow.closed)) {
        newwindow = window.open(url,'Buy','width=950,height=650,scrollbars=yes,resizable=yes');
        newwindow.focus();
    } 
    else {
        newwindow.location.href = url;
        newwindow.focus();    
    }
}  

function chkAlerts(){
    if ((newwindow == null) || (newwindow.closed)) {
        //Do something
        alert('now window is closed show alerts');
    }
}
</code></pre>

<p>With this code I am always getting </p>

<pre><code>alert('now window is closed show alerts');
</code></pre>
