Assets/colorchange.cs(4,14): error CS0101: The namespace `global::' already contains a definition for `DelegateMenu'

using UnityEngine;
using System.Collections;

public class DelegateMenu : MonoBehaviour
{
//we have to declare a delegate so that we can use it in the OnGUI function
private delegate void MenuDelegate();

//in order to use a delegate we need to create a variable of MenuDelegate type so that it can be used throughout the code.
private MenuDelegate menuFunction;

//these variables are only here because it is cheaper to access a value from memory instead of through a static class
private float screenHeight;
private float screenWidth;
private float buttonHeight;
private float buttonWidth;

// Use this for initialization
void Start ()
{
	screenHeight = Screen.height;
	screenWidth = Screen.width;
	
	buttonHeight = screenHeight * 0.3f;
	buttonWidth = screenWidth * 0.4f;
	
	//here we set the menuFunction to point to the anyKey function, which is further down in the code
	menuFunction = anyKey;
}

void OnGUI()
{
	//in order to use a delegate we just call it like a function. Simple!
	menuFunction();
}

//in order to change the GUI we just change the function that menuFunction points to. It will basically take care of itself from that point.
void anyKey()
{
	//check if the user pressed anything, if it did, change the menuFunction to show the main menu
	if(Input.anyKey)
	{
		menuFunction = mainMenu;
	}
	
	//this is just text in the center of the screen telling the user to press any key
	GUI.skin.label.alignment = TextAnchor.MiddleCenter;
	GUI.Label(new Rect(screenWidth * 0.45f, screenHeight * 0.45f, screenWidth * 0.1f, screenHeight * 0.1f), "Press any key to continue");
}

//mainMenu only has two buttons in the version, one to play the game, and one to quit the game
void mainMenu()
{
	if(GUI.Button(new Rect((screenWidth - buttonWidth) * 0.5f, screenHeight * 0.1f, buttonWidth, buttonHeight), "Start Game"))
	{
		Application.LoadLevel("Level1");
	}
	
	if(GUI.Button(new Rect((screenWidth - buttonWidth) * 0.5f, screenHeight * 0.5f, buttonWidth, buttonHeight), "Quit Game"))
	{
		Application.Quit();
	}
}

}

i dont know whats wrong with it

aha
ok