Can someone help me with this error?

I am new to unity and I am making my first game, I came across this error and I have no idea what it means.

Error:
Assets/first person/NewBehaviourScript.cs(24,45): error CS0176: Static member `UnityEngine.Camera.main' cannot be accessed with an instance reference, qualify it with a type name instead

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class NewBehaviourScript : MonoBehaviour {
5.  
6.     public float movemetspeed = 5.0f;
7.     public float mousesensitivity = 5.0f;
8.     public float updwnrange = 80.0f;
9.  
10.     // Use this for initialization
11.     void Start () {
12.    
13.     }
14.    
15.     // Update is called once per frame
16.     void Update () {
17.         //rotation
18.  
19.         float rotX = Input.GetAxis ("Mouse X") * mousesensitivity;
20.         transform.Rotate (0, rotX, 0);
21.  
22.         float rotupdwn = Input.GetAxis ("Mouse Y") * mousesensitivity;
23.  
24.         float currentupdwn = camera.main.transform.rotation.eulerAngles.x;
25.         float desiredupdwn = currentupdwn - rotupdwn;
26.  
27.         Camera.main.transform.rotation = Quaternion.Euler (desiredupdwn, 0, 0);
28.  
29.         //movement
30.         float forwardspeed = Input.GetAxis ("Vertical") * movemetspeed;
31.         float sidespeed = Input.GetAxis ("Horizontal") * movemetspeed;
32.  
33.         Vector3 speed = new Vector3 (sidespeed, 0, forwardspeed);
34.  
35.         speed = transform.rotation * speed;
36.  
37.         CharacterController cc = GetComponent<CharacterController>();
38.  
39.         cc.SimpleMove (speed);
40.     }
41. }//
42.  

 

camera.main isn't the same thing as Camera.main. Note the capital C

 

thanks for that.