I was wondering if there were any good scripts that would detect if a user had flash or not and if they didn't replace the flash element with php or html coding...for instance:

If I had a navbar that was flash based and my users did not have flash on their machines...I now would want them to use a javascript based or html bases nav bar ion the same spot with the same size...how would I do this as far as coding go's?...any good and efficient suggestions?

Thanks