DelAllButton.cs

using UnityEngine;
using System.Collections;

public class DelAllButton : MonoBehaviour {
	
	private GameObject Del;	
	
	void Start () {
	}
	
	void OnGUI()
	{
		if(GUI.Button(new Rect(300, 10, 100, 50), "DelAll"))
		{
			Del = GameObject.Find("CubeParent");
			Del.BroadcastMessage("OnMouseDown");
		}
	}
}