adding html code for mobile website

Hi

I have to add the following code in order to redirect visitors to my mobile website (I don't use the motoCMS mobile version)

<script src="http://static.dudamobile.com/DM_redirect.js" type="text/javascript"></script>
<script type="text/javascript">DM_redirect("http://m.bed-breakfast-provence.fr");</script>

I have read on technical support and knowledge base that I have to add these lines here :

layout.tpl.php

I have done it, but apparently it doesn't work.

Can you please help ?

Merci !

Charles