An object reference is required to access a non static member.

It says that an object reference is required to access a non static member for Camera.cullingMask. Help!

using UnityEngine;
using System.Collections;

public class StartMenuControl : MonoBehaviour
{
	public bool isStart;
	public bool isLoad;
	public bool isOptions;
	public bool isQuit;


	void OnMouseUp()
	{
	if (isQuit == true)
		{
			Application.Quit ();
		} 
	else if (isOptions == true) 
		{
			Camera.cullingMask |=(1<<LayerMask.NameToLayer (" Options Screen"));
			   Camera.cullingMask &= ~(1<<LayerMask.NameToLayer("Main Screen"));
		}
	}
}

If you only have one Camera and it’s “Main” does Camera.main.cullingMask… work?