Get the radio button value in a form

Question

I'm still pretty new in this and probably this should be simple enough but for some reason is not working for me, I have this code in a JSP that is working.

 <form action="Controlador">
                <div class="form-group">
                    <p><strong>Bienvenido al sistema</p></strong>
                    </div>
                    <div class="form-group">
                        <label>Usuario:</label>
                        <input class="form-control" type="text" name="txtUsuario"">
                    </div>

                    <div class="form-group">
                        <label>Password:</label>
                        <input class="form-control" type="text" name="txtPassword"">
                    </div>

                    <div class="form-group">
                        <label>Tipo Usuario:</label>
                        <input class="form-control" type="text" name="txtTipoUsuario">
                    </div>

                <input class="btn btn-danger- btn-block" type="submit" name="accion" value="Ingresar">

I just want to change "txtTipoUsuario" to a radio button so I don't have to write manually a value in the form, I tried some possible solutions but nothing worked, I can't get to send the value correctly, I wonder what I'm missing