Well, to attach the external Javascript file, just have this in your code:
PHP Code:
<script type="text/javascript" src="js/myjavascriptfile.js" ></script>
<link rel="stylesheet" type="text/css" href="css/mycssfile.css" />
If your JS file uses
JQuery, include this
JQuery source link for the latest JQuery version. So that you'll have this:
PHP Code:
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript" src="js/myjavascriptfile.js" ></script>
<link rel="stylesheet" type="text/css" href="css/mycssfile.css" />
If you need help on the onmouseover effect, JQuery makes it very easy for you. Check out
http://api.jquery.com/hover/