<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
    function get_onclick(){
        $("li").click(function (e){
            var onclick_val= $(e.target).attr("onclick");
            alert(onclick_val);
        })
    }
    $(function(){get_onclick()}); 
</script>
<ul>
    <li onclick="hello()">hello</li>
    <li onclick="world()">world</li>
</ul>

            window.onload = function(){
                var lis = document.getElementsByTagName('li');
                for (var i in lis) {
                    lis[i].onclick = function() {
                        alert(this.getAttribute('onclick'));
                    };
                }
            };