@if (Request.IsAuthenticated) {
    <text>
        Здравствуйте, @Html.ActionLink(User.Identity.Name, "Manage", "Account", routeValues: null, htmlAttributes: new { @class = "username", title = "Управление" })!
        @using (Html.BeginForm("LogOff", "Account", FormMethod.Post, new { id = "logoutForm" })) {
            @Html.AntiForgeryToken()
            <a href="javascript:document.getElementById('logoutForm').submit()">Выйти</a>
        }
    </text>
} else {
  
}