Ajax not returning values to chrome but is to FF

I am new to Ajax and have been following a tutorial from JQuery.com. I have set up a script that is very simple, when an h2 element is clicked a php script is called that returns some xml which JQuery the uses to replace the current h2 contents. Below is the javascript content:

$(document).ready(function () {

$('h2').click(function(e){
  e.preventDefault();
  var user = $(this);
  $.post("ajax.php", {id: "1"}, function(xml) {
    // format result
    var result = [
      "Thanks for rating, current average: ",
      $("average", xml).text(),
      ", number of votes: ",
      $("count", xml).text()
    ];
    // output result
    $(user).html(result.join(''));
  } );

});
});

And here is the php script:

<?php 
$av = 5;
$xml = "<ratings><average>$av</average><count>$av</count></ratings>";
header('Content-type: text/xml'); 
echo $xml; 
?>

In Fi开发者_如何学Pythonrefox I get the expected: "Thanks for rating, current average: 5, number of votes: 5"

but in Chrome I get: "Thanks for rating, current average: , number of votes: "

As you can see, Chrome doesnt recognise anything passed back in the xml. I am running this on a regular dreamhost hosting account with no additions made to the server by me.

Any help would be greatly appreciated.

Regards Luke

please check the contents of variable xml in chrome. If it's empty, try to set the dataType explicitly:

$.post("ajax.php", {id: "1"}, function(xml) {
// format result
var result = [
  "Thanks for rating, current average: ",
  $("average", xml).text(),
  ", number of votes: ",
  $("count", xml).text()
];
// output result
$(user).html(result.join(''));
}, 'xml');