You can extract elements from the XML by creating a JQuery object with it. E.g. to create a link:
<script type="text/javascript">
$(document).ready(function(){
$("#url_shorten_form").submit( function () {
$.post(
'post_linkme.php',
$(this).serialize(),
function(data){
var shortLink = $(data).find("shortlink").text();
var longLink = $(data).find("longlink").text();
var link=$("<a></a>").attr("href",shortLink).text(longLink);
$("#result").html(link);
},
"xml"
);
return false;
});
});
</script>