如何使用XDomainRequest正确重写Ajax请求以使其在IE 8 +中工作？

$.ajax({
    type: "GET",
    url: url,
    success: function(xml) {
        $('.post-msg').append(processXml(xml, config));
    },
    error: function(jqXhr, textStatus, errorThrown) {
        var errorMsg = "Request on url: " + url + " failed: " + textStatus + " error:" + errorThrown;
        alert(errorMsg);
    }
});