PHP variable in my HTML5 ?

if it's echo'd:

var xmlhttp;

if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}

xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
alert(xmlhttp.responseText);
}
}

xmlhttp.open("GET", "date.php", true);
xmlhttp.send();

///////////////

where date.php:

<?php
$dateVar = date("M-d-Y g:i A");
echo $dateVar;
?>