WinJS – how to cancel the navigation from a page ?

Did you use the WinJS navigation framework ? If not, you should really take a look at it because it’s can be really useful and powerful ! Today I needed to cancel the navigation from a page based on the current state of the page. It could be useful to zoom out of a semantic zoom instead of navigating back when the user tap the little arrow (windows phone habit ). I was wondering how I would be able to code this and it turned out that this is pretty easy.