Sound on click

So i am still making an fps game but how to do this when i click the left mouse button the sound plays the stop when i click again it do the same thing how to do that pls help

This should do it. All you need is to have an AduioSource with a sound attached to it. on the same object his script is on:

AudioSource aSrc;

void Start () {
 aSrc = GetComponent<AudioSource> ();
}

void Update () {
if (Input.GetKeyDown (KeyCode.Mouse0))
   aSrc.PlayOneShot (aSrc.clip);
}

use public AudioSource Sound1; and then assign the sound you want to Sound1 in the editor. In the update() function, trigger Sound1.Play(); when the mouse is clicked and Sound1.Stop(); when you click it again.