[<HttpPost>]
member x.Login (viewModel:LoginViewModel) =
    if String.IsNullOrWhiteSpace viewModel.UserName || String.IsNullOrWhiteSpace viewModel.Password then
        x.ModelState.AddModelError("", "Incorrect username or password")

    if x.ModelState.IsValid then
        let userToGet = ctx.Users |> Seq.tryFind(fun z -> z.UserName = viewModel.UserName && z.Password = viewModel.Password)

        match userToGet with
        | Some u ->
            FormsAuthentication.SetAuthCookie(u.UserName, false)
            x.RedirectToAction "index" :> ActionResult
        | None -> HttpNotFoundResult() :> ActionResult

    else x.View("login", viewModel) :> ActionResult