JS实现ajax请求头添加token

JS实现ajax请求头添加token，如何实现呢？直接上DEMO。

function updateType(type) {          
          $.ajax({
                url: mainUrl + "/order/updateType/" + localStorage.orderIds + "/" + type,
                type: "post",
                contentType: "application/json",
                dataType: 'json',
                cache: false,
                async: true,
                beforeSend: function (XMLHttpRequest) {
                    XMLHttpRequest.setRequestHeader("token", localStorage.token);
                },
                success: function (result) {
                    if (result.status === 0) {
                        window.location.href = "my-order.html";
                    } else {
                        alert(result.msg)
                    }
                }
            });
 
 
}