The jQuery ajax script below doesn't work on my site if url is without www. I checked Firebug and it doesn't send the ajax call.

$.ajax(
    {
        type: "POST",
        url: "http://www.mysite.com/beta/products.php",
        data: "page_type=index&sort=relevancerank&CartId=<?php echo $CartId;?>&HMAC=<?php echo $HMAC;?>",
        success: function(msg)
        {
            $('#content-holder').html(msg);

        },
        error: function()
        {
            alert("An error occurred while updating. Try again in a while");
        }
    });