why javascript add 1 to setInterval id?
<pre><code>$('#interviehover').hover(function(){
            IntervalId = setInterval(sec, 500)
            alert(IntervalId)
        });
        $('#interviehover').mouseout(function(){
            clearInterval(IntervalId)
            alert(IntervalId )
        });
</code></pre>

<p>after mouseout event fires i get IntervalId with added 1; for example on hover it alerts 12059, but on mouseout 12060?</p>

<p>Thanks!</p>
