AS animation of Characters

im planning of making a sideview action game. Because i want to push things a little further i want to drop the use of basic sprite animation. Im aiming at getting fluent transitions between movements via AS. So instead of switching the walking animation to jumpinganimation, i want the legs moving to the beginning of a jumping animation(actionscripted) and then jump.
I hope my explanation is clear, has anybody tried this before? Any helpfull resources?