Audio Play on Touch

Hello everyone , i want to do audio effect when button pressed i tried couple things but couldn’t find im using C# , this is my code ;

using UnityEngine;
using System.Collections;

public class Menu : MonoBehaviour {

	public GUIStyle buttonStyle ;
	public GUIStyle button2;
	public AudioClip source1;


	void OnGUI () 
	{
		if(GUI.Button(new Rect(Screen.width/250,Screen.height/10,Screen.width/2,Screen.height/5), "" , buttonStyle))
		{

			Application.LoadLevel("Level1");

		}

		if(GUI.Button(new Rect(Screen.width/120,Screen.height/3.9f,Screen.width/2,Screen.height/5), "" , button2))
		{

		}
		
		}

    }

after adding audio source and audio listener you can simply use this

audio.PlayOneShot(source1);  

but if you want to use this for effects that plays often in games you should make a pool manager for your sounds , check this links
soundMnager cs script

http://www.blog.silentkraken.com/2010/04/06/audiomanager/

http://u3d.as/content/dark-tonic-inc-/master-audio-aaa-sound-solution/3PY