my javascript Application works on firefox and chrome very well. But it seams to be broken on Internet Explorer (IE 8).
I did not get an error Message on the console
Reduce is not supported until IE 9 : https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/array/reduce#Browser_compatibility
That link does have a workaround bit of code for browsers that don't support reduce.
You can also find other ES5 JavaScript array functions polyfills here:
http://tech.pro/tutorial/1834/working-with-es5-javascript-array-functions-in-modern-and-legacy-browsers#indexof