Gun Sound On Mousedown

I need a script that tells an audio to play when i click the mouse down. Ive looked everywhere and none really seem to work, if anyone can help that would be exelent.

Thanks in advance

You’ve looked everywhere? So you should have found AudioSource.Play and Input.GetMouseButtonDown.

var sound : AudioClip;

function Start(){
    audio.clip = sound;
function Update (){