How to add animation to a button

Hello,

My DPS page below contains a series of button that each have 2 actions(Goto URL{navto://} and Sound media) which work great.

However, I would like to add a simple action so that the button image "jumps up" when it is clicked.

What is the best way to achive this and can the animation action be added in addition to the existing actions for the button? I'm looking for the simplest method, as I have not used Edge or Flash.

I'm using Indesign CS5.5

Any help greatly received.

Regards,

              Iain.....