Looping Insite UL

How can I loop inside UL's LI elements in javascript?

<script type="text/javascript">

function TagSecildi(oLink) {
var content = oLink.innerHTML + ";";
var myString = $('mytags').value;
var Pos = myString.indexOf(icerik)
if( Pos == -1 ) { // not available
$('mytags').value = $('mytags').value + content;
oLink.className = 'MySelectedTag'
} else { // Var
myString = myString.substring(0, Pos) + myString.substring(Pos + content.length);
$('mytags').value = myString;
oLink.className = 'MyNormalTag'
}}
</script>

<input name="mytags" type="text" id="mytags" style="width:500px" value="Ajax; Java;">

<ul id='mevcutlar'>
<li onClick="TagSecildi(this);">Ajax</li>
<li onClick="TagSecildi(this);">Delphi</li>
<li onClick="TagSecildi(this);">JavaScript</li>
</ul>

I want to change LI tag's style if my input named "mytags" value (spereated with ; ) is equal to LI's content.