This example is much more advanced than the previous two, although the result looks deceptively simple.
Basically, this script interrogates the user's browser, and even their operating system to work out the plugins which the user has available.
To try out the plugin detector, just click on the link below. A green light is displayed for every plugin you have, a red for each one you do not have.
The main purpose of this script is not give a readout of plugins to the user, but to allow web developers to control what the user will see if they do not have a particular plugin. Instead of testing web users with a Flash movie ("do you see a dog in the box above?") you can discreetly inform them they do not have Flash installed.
Alternatively, you can be less bossy and just send them automatically to the non-Flash version of your page. That way they do not need to know that they are missing anything.
For those of you with the courage (and the time) to wade through five pages of scripts, here is a link to the code which is behind that little popup window:
plugin detector code
For those of you who can not be bothered with that, here is the code to make little popup windows. Much less complicated.
little popup windows