Building Online guitar tuner - What programming should I use for this?

Hi, I'm building an online guitar tuner. It's going to be really simple. The user clicks a switch to play a sound to tune a guitar string to. I've prepared the images for the tuner.

A green button will indicate that the switch is on and the corresponding sound will play at the same time and loop. When the switch is clicked again, the button turns red and the sound stops.

Again I've got all the graphics ready to be flipped during the event. I'm just not sure what the best programming would be and I'm not really a programmer but I think I can do this on my own.

Should I use flash, a straight script? any suggestions would be wonderful!

Images are PNG format, sounds will be MP3. With 6 strings it will look like this..

12 buttons graphics - 6 green (on) 6 red (off)...to be used for flipping during the event.

6 MP3 sound files (one for each string).

My concern is making it accessible for everyone regardless of web browser. I would like to stay away from flash if possible. If you could point me in the right direction, maybe find an article explaining something similar, I could probably do this