Need help with jQuery
<p>This my script:</p>

<pre><code>&lt;script type="text/javascript"&gt;
var auto_refresh = setInterval(
function () {
$('#alert_div').load('/check_messages.php?timestamp=&lt;?php echo TIMESTAMP2;?&gt;').fadeIn("slow");}, 180000);
$("html,body").scrollTop("alert_div",0);
&lt;/script&gt;
</code></pre>

<p>Actually, everyting works fine but... 
As you can see, every 3 minutes script loads check_messages.php file. If user has new messages <strong>messages check_messages.php</strong> outputs information, otherwise the output is empty:</p>

<pre><code>echo "";
</code></pre>

<p>I need that <code>$("html,body").scrollTop("alert_div",0);</code> <strong>exetutes only in case</strong> if php script output <strong>is not</strong> empty.</p>
