Calls between methods of application.rb

I have a set_lang() and a write_to_log() method in
app/controllers/application.rb

set_lang() calls write_to_log().

Nothing happens. I should expect that write_to_log is either called or
an exception is thrown. However, it seems that it is silently ignored.
To prove this I called write_to_log00(), which does not exist. Still
the same behavior.

Is this normal?

To make things more specific, here is my code:

# file: app/controllers/application.rb

  def write_to_log(msg)
      File.open("logfile.txt", "a") do |file|
      now = DateTime.now
        file.puts("#{now}\t#{msg}")
      end
  end

  def set_lang
    code = params[:id]
    if code != "el" && code != "en" && code != "de"
        code = "el"
    end
    @lang = code

    write_to_log("set_lang\t" + code)

    cookies[:lang] =
      {
        :value => code,
        :expires => Time.now + 1.year,
        :path => '/'
      }
    # redisplay the page in the new language
    redirect_to request.env["HTTP_REFERER"]
  end