ActionScript for your buttons:

code to use a button to move us along the timeline:
btnInstanceName.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandlerA);
function mouseDownHandlerA(event:MouseEvent):void {
gotoAndStop(1);
}




buttonInstanceName.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandlerB);
function mouseDownHandlerB(event:MouseEvent):void {
movieClipInstanceName.play();
}