Dear Paul
Thank you for your reply. I also found your post about this topic: http://arduino.cc/forum/index.php/topic,45629.0.html
But also your code will not work for me. You asked me, if I am sending \r or \n too. Sorry, but I don't know. Sorry for this question, but is the little menu at the bottom of the Arduino serial monitor to way to decided if I am sending \r and \n? I tested all four possibilities, but your code will not work for me.
Any hint?