Right now I'm letting Umbraco handle the logging in of my members through my website so I have no access to its controller. Because of this I have no way of letting the user know they have successfully logged in or not.

So how can I expand upon the preexisting umbraco login logic to let me either display something to say they've logged in, or to redirect them to a different page?

My log in view is this

@using (Html.BeginUmbracoForm<UmbLoginController>("HandleLogin"))
{
    <legend>Login</legend>

    @Html.ValidationSummary("loginModel", true)

    @Html.TextBoxFor(m => loginModel.Username, new { @class = "form-control", @placeholder = "Username" })
    @Html.ValidationMessageFor(m => loginModel.Username, "", new { @class = "alert-danger", @role = "alert" })
    <br />

    @Html.PasswordFor(m => loginModel.Password, new { @class = "form-control", @placeholder = "Password" })
    @Html.ValidationMessageFor(m => loginModel.Password, "", new { @class = "alert-danger", @role = "alert" })
    <br />

    <button class="btn btn-default">Login</button>
}