Pause menu error NullReferenceException:Object reference not set to an instance of an Object .js

why is this error coming up on js12?`enter code here

pragma strict
	var pauseCanvas : Canvas;
	function Start () {
   		Screen.lockCursor = true;
   		Cursor.visible = false;
  }

	function Update () 
{
	  if (Input.GetKeyDown(KeyCode.Escape))
	{
		(gameObject.Find("First Person Controller").GetComponent("MouseLook") as MonoBehaviour).enabled = false;
		(gameObject.Find("Main Camera").GetComponent("MouseLook") as MonoBehaviour).enabled = false;
		pauseCanvas.enabled = true;
		Time.timeScale = 0;
		Screen.lockCursor = false;
		Cursor.visible = true;	
	}
 }

	function Resume () {
		(gameObject.Find("First Person Controller").GetComponent("MouseLook") as MonoBehaviour).enabled = true;
		(gameObject.Find("Main Camera").GetComponent("MouseLook") as MonoBehaviour).enabled = true;
		pauseCanvas.enabled = false;
		Time.timeScale= 1;
		Screen.lockCursor = true;
		Cursor.visible = false;	
	
}

	function ExitGame () {
		Application.LoadLevel ("openingexit");
	    pauseCanvas.enabled = false;
		Time.timeScale= 1;
		
		}
		
		
	function ExitToMain () {
		Application.LoadLevel ("gui");
	    pauseCanvas.enabled = false;
		Time.timeScale= 1;
		
		}

gameObject represents the current GameObject which has the edited script on. The right method call is:

GameObject.Find("First Person Controller").GetComponent("MouseLook") as MonoBehaviour).enabled = true;

with capital ā€˜Gā€™.