MP3 Player Button Issues

Hi, I’ve made a very basic mp3 player with simple play and stop buttons and it works just fine. However I have noticed that when you click play again while the song is playing it plays the song again from the start over the top. Same if you click it 3 times 4 etcetc. I have no idea how to disable the button while the song is playing/until the user clicks stop. This is the code I have on the play button:
on (release) {
weddingSound = new Sound(this);
weddingSound.start(0, 99);
This is the final part of a website I built and the owner is holding out on payment until this is done, so any help is greatly appreciated!!