public function select_course()
{

$data['users_id']=$this->input->post($this->session->userdata('users_id'));

    $query =$this->db->insert('gp_approval_course',$data);

    if ($query)
    {
        return true;
    }
    else
    {
        return false;
    }
    }

public function add_course()
 {

        $this->load->model('model_users');


        if ($this->model_users->select_course())
        {
        echo "You have selected a course to enroll on to!";
        echo ($this->session->userdata('users_id'));
        return true;
        }
        else

        {
         echo "Database problem";
         return false;
        }


 }

$data['users_id']=$this->input->post($this->session->userdata('users_id'));

$data['users_id']=$this->session->userdata('users_id');
$data['course_id'] = $this->input->post('your_course_id_var');