Seamonkey: How to watch Youtube video the old fashion way

Youtube is now using html5

This is great obviously, because it means by default the internet browser doesn't need any plugin.
But let say you want to read your video the old fashion way using adobe Flash
well you actually can ... just by adding the url &nohtml5=1

for example:
https://www.youtube.com/watch?v=4h_OSURFicY&nohtml5=1

This will open the video and use adobe flash (instead of html5)
if you are not sure - just right click on the video and you should see this: