Well, I’ve removed the code from the header.php so it no longer appears on the test link mentioned above. So it seems like I cannot make it work.
Just to make sure, I haven’t missed something else in the process, the steps should be as follows, right?
1. Install php browser detection plugin
2. Activate plugin
3. paste php code (as mentioned in my initial comment) into either snippet plugin, functions.php or header.php
Thanks.