Play sound only when button is pressed

I want to play sound only when button is pressed but i don’t know how to do it.

Any ideas?

Button script that i’m using.

using UnityEngine;
using System.Collections;

public class ButtonSound : MonoBehaviour
{
    bool isOn;
    public Transform Button;
    public AudioClip beep;

    private AudioSource source;

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

    public void OnMouseUp()
    {
        GetComponent<Renderer>().material.color = Color.gray;
        Button.transform.localPosition = new Vector3(0, 0.2f, 0);
    }

    public void OnMouseDown()
    {
        GetComponent<Renderer>().material.color = Color.green;
        Button.transform.localPosition = new Vector3(0, 0.2f, 0);
        

        isOn = !isOn;
        if (isOn)
        {
            //don't play sound???
        }
        else
        {
            //play sound???
        }
    }
}

I know how to do it!

This script does work just like i wanted.

using UnityEngine;
using System.Collections;

public class ButtonSound : MonoBehaviour
{
    public Transform Button;

    public void OnMouseUp()
    {
        GetComponent<Renderer>().material.color = Color.gray;
        Button.transform.localPosition = new Vector3(0, 0.2f, 0);
        this.GetComponent<AudioSource>().Stop();
    }

    public void OnMouseDown()
    {
        GetComponent<Renderer>().material.color = Color.green;
        Button.transform.localPosition = new Vector3(0, 0.2f, 0);
        this.GetComponent<AudioSource>().Play();
    }
}