Counting <li>s
HTML
<script>
var ul = document.getElementById('listing');
function countLi(){
alert("There are "+ul.getElementsByTagName('li').length+" Li-Elements in this Documnet!");
}
</script>
<input type="button" onclick="countLi()" value="Count the Li's!"/>
<ul id="listing">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>