Been quite a while since you asked, but are you asking about something like this (not tested)?
In /blocks/your_block/controller.php:
class YourBlockBlockController extends BlockController (...publicfunction getJavaScriptStrings(){returnarray('id-required'=> t('You must enter an ID.'),'pin-required'=> t('You must enter a PIN number.'));}}
In /blocks/your_block/controller.php:
In /block/your_block/auto.js: