[SOLVED] Fast redirect when loading a page

Fast redirect when loading a page

I want to redirect the user from the login page to an inner page if he has certain cookies, I placed a script at the top of the page, but I still see the login page for a split second.

Is there a way to make it faster or pause loading the rest of the DOM so the page won't appear if it's going to redirect?

<html>
<script src="script/jquery-3.1.1.min.js"></script>
<script src="script/js.cookie.js"></script>
<script>
(function () {
    if (Cookies.get("username")) {
        $.ajax({
            data: {
                "username": Cookies.get("username"),
            },
            url: "login",
            success: function (response) {
                document.open();
                document.write(response);
                document.close();
            }
        });
    }
}());

Alternatively, is there a way to make it send those cookies in the first request for the server? i.e. when the user requests the root url of the site. (I'm using Tomcat)

Solution

Keep th whole page hidden initially somethig like

<div id="login" style="display:hidden">....</div>

and in code if cookie is not present dispaly the page else redirect without showing the login form

(function () {
    if (Cookies.get("username")) {
        $.ajax({
            data: {
                "username": Cookies.get("username"),
            },
            url: "login",
            success: function (response) {
                document.open();
                $("#login").hide();
                document.write(response);
                document.close();
            }
        });
    }
   else
   {
     $("#login").show();
   }