actually you need write events to call the appropriate function, and call the javascript function from that event, see the following
<script language="javascript>
function go(val) {
alert("selected option = "+val);
}
</script>
<select align="left" id="list" onchange="go(this)>
<option...
Since the servlet is mapped to "/FileUpload", that's what should be in the "action" attribute (without the leading slash). Package and class names have no place there.