Windows Phone 7 JavaScript doesnt work

Windows Phone 7 JavaScript doesnt work

I have created a mobile Application with ASP.NET MVC 4 and jQuery mobile. It works fine on Android and
i Phone but there are different Problems when running it on a Windows Phone 7 . The Java Script on Checkboxes
doesnt work...

has anybody an idea ...

The Site is Qr-Joker.de....the Problems are on the Login/Register Page...