Error Handling Best Practice?

Dear All, 

Seemingly one of the best methods for telling people about errors in form data is to allow the user to submit the form, then by either by client-side or server-side means validate the data.  If the data contains errors a message box is placed before the form with all the error messages in it, and focus (visual and keyboard) is taken to this box (http://www.w3.org/TR/2013/NOTE-WCAG20-TECHS-20130905/SCR32).  At least, this is one of the best methods on desktop…

Trying to translate this concept to a mobile is a little difficult, due mostly to the smaller screen size - as content pushed in at the top moves all the other content down "below the fold".

I've done a little research around HTML5 validation, but the inconsistent native support / AT support means the method cannot be broadly relied upon.  The million and one JavaScript validation methods are also an option for telling people if the value they have entered is correct, but it is also a lot more confusing that the single error message box (mentioned above).

So, in your opinions what would be the best "best practice method" for error handling and error presentation on a mobile.

All the best 

Alistair