Demo
<input class='need-confirm' data-master='change' type='text' size='10' data-oldvalue='change me' value='change me'>

Behavior for change events:
When a change event occurs on an element with data-master="change", the
user will be asked for confirmation.

If the user confirms, the original change proceeds normally.
If the user cancels, a custom nochange event is dispatched — allowing you to
handle the rejection (for example, to reset the input value to its previous state).