Server side Flash detection

Hi,

I try to detect the Flash plugin in user borwsers with a PHP script. I found a tutorial that recommended reading the global $_SERVER[‘HTTP_ACCEPT’]. it should contain the string “shockwave-flash” if the plugin is installed.

The problem is that Mozilla, though is supposed to support it does not. MSIE does have the string, and i didin’t test any other browser.

Does anyone have a clue what can be done, or another way to detect the plugin at the server side?

Thanks