نوشتن متن به صورت متحرک

HTML:

<div style="position:relative;left:0px;top:0px">
<span id="highlighter" style="position:absolute;left:0;top:0;font-size:18px;font-family:Verdana;background-color:yellow;clip:rect(0px 0px auto 0px)"></span>
</div>
<script type="text/javascript">
/*
www.parsigold.com/
*/

var tickercontents=new Array()
tickercontents[0]='welcome to a persian site <a href="http://parsigold.com">www.parsigold.com</a>!'
tickercontents[1]='free download <a href="