I want to run it after running the demo, the demo1 wait three seconds .However, this script is ignored the run . The error is not .

using UnityEngine; using System.Collections;

public class SecondController : MonoBehaviour {

 public void ModeSelect(){
     StartCoroutine(LoadAfterDelay());
 }

 IEnumerator LoadAfterDelay(){
     Application.LoadLevel("demo");
     yield return new WaitForSeconds(3);
     Application.LoadLevel("demo1");
 }

}