Forms Authentication doesn't work in live application

I have setup a simple login with Forms Authentication that works fine on my localhost in an ASP.NET MVC app

But when I published the website into a live application on the web the Forms Authentication doesn't work. What am I doing wrong?

Here is my code:

<system.web>
        <authentication mode="Forms">
            <forms loginUrl="~/Home/Login" timeout="30" />
        </authentication>
</system.web>

Controller:

    public ActionResult LoginUser(string useame, string password)
    {
        if (ConfigurationManager.AppSettings["UserName"] == useame && ConfigurationManager.AppSettings["Password"] == password)
        {
            FormsAuthentication.SetAuthCookie(useame, false);

            retu RedirectToAction("Index");
        }
        retu RedirectToAction("Index");
    }

Javascript:

$("body").on("click", "#loginbutton", function (e) {

$("#loginbutton").attr("href", "/loginuser?useame=" + $('[user]').attr('user') + "&password=" + $('[pass]').attr('pass'));

});

Why does this not work in a live-application?