JQuery :: Load Php File Into A Div?

I'm trying to load a php file (load.php) into a div (<div id="randomdiv"></div>) I'm not sure if i show be using .load [URL] or if im doing it right however i'm trying this:

<script>
$('#randomdiv').load('load.php');
</script>

then in index.php i've this:

<div id="randomdiv"></div>

basically what i'm trying to do is display a file into a div (soon as the page loads), and then use .load to refresh that div without having to refresh the pageevery time.

<script>
$(function() {
$("#refresh").click(function(evt) {

[code]....