How to tell if obj is jquery or plain javascript
<p>This is probably a stupid question but is there a way to tell programmatically if the object is jquery or just plain javascript?</p>

<p>For example:</p>

<pre><code>Utils.Listbox.MoveItemsUp = function(listbox) {

    if(listbox.isJquery()) {
        listbox.each(function(){}); 
    }
    else {
        for(var i = 0; i &lt; listbox.options.length; i++){}
    }
};
</code></pre>
