Field-by-field confirmation popup

Hi, I'm relatively new to Ruby on Rails. I've searched and can't find a
straightforward answer to my particular need. There are actually two
related situations I need to find solutions for.

1. On a data entry form, for certain fields I want to do some
validation right after the user leaves the field (rather than wait
until the entire form is completed). If invalid, I want a modal window
to pop up with my composed message in it and an OK button. When the
user presses OK, control returns to the data entry form remaining in
the problem field.

2. On a data entry form where an existing record is being updated, if
the user changes a non-empty field to different value in any field
(with a few exceptions), I want a modal window to pop up with a
confirmation message and OK and Cancel buttons. When the user presses
OK, control continues normally to the next field on the form. When
Cancel, the user's change will be reversed (restoring the previous
value to the field) and control remains in the problem field.

Is there one simple way to do each of these two things (hopefully DRY
for the second one)?

Thanks,
Shauna

You're going to need to use javascript to do this, not rails.

shauna wrote: