TypeError: elem.nodeName.toLowerCase is not a function

var noData = elem.nodeName && jQuery.noData[ elem.nodeName.toLowerCase() ];

<!-- for tabs -->
<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.4/themes/smoothness/jquery-ui.css">
<script src="http://code.jquery.com/ui/1.10.4/jquery-ui.js"></script>

<!-- for graph dracula framework -->
<script type="text/javascript" src="js/raphael-min.js"></script>
<script type="text/javascript" src="js/dracula_graffle.js"></script>
<script type="text/javascript" src="js/dracula_graph.js"></script>

<!-- my files -->
<script type="text/javascript" src="settings.js"></script>
<script type="text/javascript" src="algorithms.js"></script>

 <script>
$(function() {
    $( "#tabs" ).tabs();
});
</script>

// A method for determining if a DOM node can handle the data expando
acceptData: function( elem ) {
    if ( elem.nodeName ) {
        var match = false;
        if (typeof elem.nodeName.toLowerCase != 'undefined')
            match = jQuery.noData[ elem.nodeName.toLowerCase() ];

        if ( match ) {
            return !(match === true || elem.getAttribute("classid") !== match);
        }
    }

    return true;
}