Accessing parent object camera

I need to set the clear flags of the player's camera to black when I display the sniper sight. I have written a script however it throws the exception ' The name `cam' does not exist in the current context'.

script;

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class awpScopeIn : MonoBehaviour {
5.  
6.     public Texture scopeGUI;
7.     private bool _isScoped = false;
8.     public Color color = Color.black;
9.        
10.     void Start()
11.     {
12.         Camera cam = GetComponentInParent( typeof(Camera) ) as Camera;
13.         cam.clearFlags = CameraClearFlags.SolidColor;
14.     }
15.    
16.     void OnGUI()
17.     {
18.         float width = 600;
19.         float height = 600;
20.        
21.         if (_isScoped) {
22.             GUI.DrawTexture (new Rect ((Screen.width / 2) - (width/2), (Screen.height / 2) - (height/2), width, height), scopeGUI);  
23.            
24.         }
25.     }
26.    
27.     void Update()
28.     {
29.         if(Input.GetButtonDown("Fire2"))
30.         {
31.             _isScoped = !_isScoped;
32.             cam.backgroundColor = color;
33.         }
34.     }
35. }
36.  

 

"cam" is a local scoped variable in Start. Try something like this:

Code (CSharp):

1.     public Texture scopeGUI;
2.     private bool _isScoped = false;
3.     public Color color = Color.black;
4.     private Camera cam;
5.    
6.     void Start()
7.     {
8.         cam = GetComponentInParent( typeof(Camera) ) as Camera;
9.         cam.clearFlags = CameraClearFlags.SolidColor;
10.     }

 

This threw no exceptions although the camera's clear flags didn't change?