I have a game over scene that is supposed to show score and a retry button bu no matter how many times I reapply the script it still doesn't take effect.

There are no error messages, console stuff, anything, I just apply the scripts to my main camera in the empty scene and nothing happens to it. please help! The code is as follows:

using UnityEngine;
using System.Collections;

public class GameOverScript : MonoBehaviour {
	
	int score = 0;

	void Start () {
		score = PlayerPrefs.GetInt ("Score");
	}

	void OnGui()
	{
		GUI.Label (new Rect (Screen.width / 2 - 40, 50, 80, 30), "GAME OVER");

		GUI.Label (new Rect (Screen.width / 2 - 40, 300, 80, 30), "Score: " + score);
		if (GUI.Button (new Rect (Screen.width / 2 - 30, 350, 60, 30), "Retry?"))
		{
			Application.LoadLevel (0);
		}
	}

}

I just drag that onto the main camera, save the Game Over scene, fail at my own game, and all I get for my efforts is a blue default camera screen. What do I do?

the method name is OnGUI()

Maybe you didn’t add the scene to the scene list?