Try this:
$(function(){
$('.form :input').change(function(e){
console.log($(e.target).attr('id'));
});
});
here e.target
is your current element which got the event of change
.
As per your comment:
How we can say which field is changed.
you need to assign an unique identifier to all your input type text
:
<input type='text' id='a'>
<input type='text' id='b'>
..................
then use this:
$('.form :input').change(function(e){
$('#log').prepend('<p>Form changed ' + $(e.target).attr('id') + '</p>')
});