using UnityEngine;
using System.Collections;

public class scene9 : MonoBehaviour {

	// Use this for initialization
	public Texture2D startWin;
	public Texture2D setupWin;

	private bool startwindow = true;
	private bool setupWindow = false;
	void Start () {
		Invoke ("startwindowFun", 2);
		Invoke ("setupwindowFun",3);
		Invoke ("loadScene11",5);
	}
	
	// Update is called once per frame
	void Update () {
	
	}
	public void startwindowFun() {
		startwindow = !setupWindow;
		}
	public void setupwindowFun() {
		startwindow = setupWindow;
		setupWindow = !setupWindow;
	}
	public void loadScene11() {
		Application.LoadLevel ("Scene11");
	}

	void OnGUI() {
			
				if (startwindow) {
						GUI.Label (new Rect (270, 300, 160, 100), startWin); 
			
			
				}

				if (setupWindow) {
						GUI.Label (new Rect (270, 300, 300, 100), setupWin);
			
				}

		}	
	
}

The above code works to load a texture one after the another at a specified time.It worked for me.