You can do something like this to read your nodes.
Also you can find some explanation in this page http://www.compoc.com/tuts/
<script type="text/javascript">
var markers = null;
$(document).ready(function () {
$.get("File.xml", {}, function (xml){
$('marker',xml).each(function(i){
markers = $(this);
});
});
});
</script>