Unity: Menu Item

MenuItem.cs

using UnityEngine;
[RequireComponent (typeof (Collider))]
public class MenuItem: MonoBehaviour {

	public KeyCode m_shortcut = KeyCode.Space;
	public bool m_QuitButton = false;
	public string m_levelName;
	
	public Color m_colorNormal = Color.white;
	public Color m_colorHighlighted = Color.red;
	
	void Start() {
		renderer.material.color = m_colorNormal;
	}

	void Update() {
		if (Input.GetKeyDown(m_shortcut))
            OnMouseDown();
	}

	void OnMouseEnter() {
		renderer.material.color = m_colorHighlighted;
	}

	void OnMouseExit() {
		renderer.material.color = m_colorNormal;	
	}

	void OnMouseDown() {
		if (m_QuitButton){
			Application.Quit();
		}

		else {
			Application.LoadLevel(m_levelName);
		}

	}
}