html5/flash in browser

[muruba]

I am wondering if there is an existing javascript solution to choose between html5/flash version of the app based on the user agent capabilities in use.

I can use http://projects.spring.io/spring-mobile/ to force html5 for mobile/tablet devices. But then for example in explorer the project works like crap so I would like to force flash and also there are many more browsers and versions that would probably be not ok with html5 app and it is better to offer Flash version if it is supported - any ready solutions for it?

Thanks!