make a clickable button that makes pause menu appears.,How can i make a pause button on my game screen than shows pause menu when i click it?

i want to make a buuton that its clickable and it shows my pause menu, i have created a pause menu that appears when i click on my keyborrd but i want that to hapen also when i build the game on android
this is the script m using.

using UnityEngine;
using System.Collections;

public class pausemenu : MonoBehaviour {

public GameObject PauseUI;

private bool paused = false;

void Start(){
	PauseUI.SetActive (false);
}

void Update(){
	if(Input.GetButtonDown("Pause")){
		paused = !paused;

}
	if(paused){
		PauseUI.SetActive(true);
		Time.timeScale = 0;
	}
	if(!paused){
		PauseUI.SetActive(false);
		Time.timeScale = 1;
	}

}
public void Resume(){

	paused = false;
}
public void Restart(){
	Application.LoadLevel (Application.loadedLevel);
}
public void MainMenu(){
	Application.LoadLevel (0);
}
public void Quit(){
	Application.Quit ();
}

}