Putting sound in button design time problem

Hi guys it is a simple question i try to put a sound when the button is clicked or roll over on design .

Here is how i do it

i put extra layer then put my sound on OVER frame and DOWN frame.

when i test the movie and click my button both “OVER” and “DOWN” sound is played . is there anyway to make just only “DOWN” sound that can be played without actionscripting to minimize actionscripting too much

thx