i've a unique controller where i control it all my views so from here i've got a problem. After to send data to do login i need obtain a value sended. For example, i've this controller: HomeController, in this controller i've four ActionResult:

ActionResult Index

ActionResult Login

ActionResult Cuotas

ActionResult LogOff

So, when the user login i need obtain here username to verify is already connected from my DB

HomeController:

public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult Login(string uname, string psw)
    {
        try
        {
            ViewData["uname"] = uname;
            ViewData["psw"] = psw;

            ConexionSQL sql = new ConexionSQL();
            var usuario = sql.login(uname, psw);
            var existencia = sql.usuarioOCobrador(uname, psw);

            if (existencia[0].usuario == "USUARIO")
            {
                var caracteres = Convert.ToString(psw);
                var pruebaUsuario = sql.datos(uname);


                if (pruebaUsuario[0].clave == caracteres)
                {
                    return View("Cuotas", usuario);
                }
                else
                {
                    ViewBag.Contra = "Contraseña incorrecta.";
                }
            }
            else if (existencia[0].usuario == "COBRADOR")
            {
                return RedirectToAction("Cuotas", "Home", usuario);
            }
            else
            {
                ViewBag.Usu = "Usuario incorrecto o usted no tiene los permisos para ingresar al sistema. Comuníquese con el área pertinente o el Departamento de Sistemas.";
            }
        }
        catch (SqlException ex)
        {
            throw ex;
        }
        return View("Index");
    }

        public ActionResult LogOff(string uname)
        {
            ConexionSQL conexionSQL = new ConexionSQL();
            conexionSQL.updateConectado(uname, false);
            FormsAuthentication.SignOut();
            Session.Abandon();
            return RedirectToAction("Index", "Home");
        }

        public ActionResult Cuotas()
    {
        ConexionSQL sql = new ConexionSQL();
        string uname = string.Empty;
        string psw = string.Empty;

        //Get your ViewData variables here
        if (ViewData["uname"] != null)
        {
            uname = Convert.ToString(ViewData["uname"]);
        }

        if (ViewData["psw"] != null)
        {
            psw = Convert.ToString(ViewData["psw"]);
        }
        var usuario = sql.datosCob(uname);
        if (usuario[0].conectado == false)
        {
            return RedirectToAction("Index", "Home");
        }
        else
        {
            return RedirectToAction("Cuotas", "Home");
        }
    }
}

Index View, here is the login:

        <form class="modal-content animate" onsubmit="return control()" method="post" action="@Url.Action("Login", "Home")">
            <div class="imgcontainer">
                <span onclick="document.getElementById('id01').style.display='none'" class="close" title="Cerrar">&times;</span>
                <img src="~/Images/00.png" alt="Logo" class="avatar"/>
            </div>
            <div class="container">
                <label for="uname"><b>Usuario:</b></label>
                <input type="text" id="uname" placeholder="Ingrese usuario..." name="uname" onkeypress="return soloLetras(event)"/>

                <label for="psw"><b>Contraseña:</b></label>
                <input type="password" id="psw" placeholder="Ingrese contraseña..." name="psw" onkeypress="return soloNumeros(event)"/>

                <button type="submit">Iniciar sesión</button>
            </div>
        </form>

But uname always is null, whats wrong with my code?