Display GUI on trigger

Using Unity New GUI system, Will first need to create a GUI element using Prefab and save under Resources Folder. Then upon collision trigger, instantiate the GUI prefab and display onGUI

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class PlayerContact : MonoBehaviour {

    bool ToggleGUI = false;
    bool isCreated = false;
    // Use this for initialization
    void Start () {
        //Resources.Load ("PopupMsg");
    }

    // Update is called once per frame
    void Update () {

    }
    void OnTriggerEnter(Collider other) 
    {
        if (other.gameObject.CompareTag ("Player"))
        {
            //Debug.Log ("Detected");
            ToggleGUI = true;
        }
    }

    void OnGUI(){
        if (ToggleGUI == true) {
            if(!isCreated){
                GameObject msg = (GameObject)Instantiate(Resources.Load("PopupMsg"));
            isCreated = true;
            }
        }
    }

}