Preventing users with lower Flash version from viewing my Flash file

I’ve discovered that users with lower versions of Flash player (such as 9,0,28,0) cannot display my Flash applications properly.

So I want to detect the users version of Flash player. If the version is below a certain value (not quite sure which yet, but somewhere around 9,0,40,0), I want to tell them to update their Flash version number, and redirect them to the Adobe Flash Player download page
http://www.macromedia.com/software/flash/about/