Why doesnt my simple html5/javascript page work in IE9?

[nippynoo]

This simple page works fine in Chrome, but not in IE9. Does anyone know what have I done wrong?
http://itsuite.it.brighton.ac.uk/jjl/html5/test.html

I've just wasted the whole morning getting nowhere Its like its blocking the script, but how come javascripts on other webpages work just fine?
Thanks.

 

[nippynoo]

arghhh!... seems like IE9 doesnt like the "const"!!! just changed it to "var"