asp .net web api and backbone.js

public static void SetAuthInfo(Guid Id, string Email, string FullName, string Role, Guid PersonId, Guid OrganizationId
            , string exchangeUID, string exchangePWD, string exchangeDomain,int? fileManagerPermission)
        {
            if (HttpContext.Current.Response.Cookies[FormsAuthentication.FormsCookieName] != null)
            {
                HttpContext.Current.Response.Cookies.Remove(FormsAuthentication.FormsCookieName);
                
            }

            string fullName = FullName;

            var ticket = new FormsAuthenticationTicket(
                1,
                fullName,
                DateTime.Now,
                DateTime.Now.AddMinutes(FormsAuthentication.Timeout.TotalMinutes),
                false,
                string.Format("{0}_{1}_{2}_{3}_{4}_{5}_{6}_{7}_{8}_{9}", Email, Id, FullName, Role, PersonId, OrganizationId, exchangeUID,
                July.Common.Encryption.Encrypt(exchangePWD), exchangeDomain, fileManagerPermission==null?0:fileManagerPermission));

            var encryptedTicket = FormsAuthentication.Encrypt(ticket);
            var cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket)
            {
                HttpOnly = true,
                Secure = FormsAuthentication.RequireSSL
            };
            var ASPSESSID = new HttpCookie("ASPSESSID")
            {
                HttpOnly = true,
                Secure = FormsAuthentication.RequireSSL,
                Expires = DateTime.Now.AddMinutes(FormsAuthentication.Timeout.TotalMinutes)
            };


            var identity = new GenericIdentity(ticket.Name);
            var principal = new CustomUserPrincipal(identity, Id, Email, Role, FullName, PersonId, OrganizationId, exchangeUID, exchangePWD, exchangeDomain);
            HttpContext.Current.User = principal;
}

<authentication mode="Forms">
    <forms defaultUrl="~/Home/Index" timeout="30" name="FormsAuthentication" loginUrl="~/Account/Login" />
  </authentication>
  <authorization>
    <deny users="?" />
  </authorization>