Dirty Fields in Rails 1.2.6

Hi Friends,

I am using Rails 1.2.6 in my application. I need to use the
functionality of "dirty fields" (getting previous value of an object's
attributes). I know "Dirty fields" features are already in edge rails.
But i want to do the same in my current rails version... any ideas?

i tried the dirty plugin which is given here

After including this module (from the above url) to my active record
base class, my active record object are able to show the status -
whether object is changed or not (using the method - obj.changed? ) but
they are unable to show the changed values, instead it always give an
empty hash ( method - "obj.changes")

I need to get the previous value for the modified object's attributes

can anybody help on this?