А так работает?
index.php:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Example</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
<script type="text/javascript">
$.get('index3.php?param1=1¶m2=2',function(html) {
$('.div').html(html);
});
</script>
</head>
<body>
<div class="div"></div>
</body>
</html>
index3.php:
<?php
if(isset($_GET['param1']) && isset($_GET['param2'])) {
echo'param1: '.$_GET['param1'].' param2: '.$_GET['param2'];
} else {
header('Location: http://'.$_SERVER['HTTP_HOST']);
exit;
}
?>