I have created a PHP script that pushes users to switch to a relevant browser. It works as follows: A user triggers her browser to ask for your page (across the Web). The page is different depending on the user agent. A message only shows on the web page only if the client uses a “bad” browser. The message can be anything. By default it proposes to switch to Firefox.
The script is free to be re-used. –FÃ©licien Breton