I am brand new to jQuery[p.s. i love you]

I have a web form that has a list of items. When the user makes a selection the list may grow or shrink.

When the list grows and the submit button at the bottom of the form is places outside below the view i scrollTo the bottom nice and smooth [this is all good].

What I am looking to do is mimic this in reverse.

Currently if the list shrinks and form size shrinks the button stays at the bottom but the resizing is very "hard".

I would like to animate that if possible just not sure what events to attach to and what functions i should use to accomplish this.

THANKS IN ADVANCE