ScreenToWorldPoint error (C#)

When I use this code I get an error saying :

error CS1061: Type Camera' does not contain a definition for ScreenToWorldPoint’ and no extension
method ScreenToWorldPoint' of type Camera’ could be found (are you
missing a using directive or an
assembly reference?)

Heres the code:

using UnityEngine;
using System.Collections;

public class PlayerMovement : MonoBehaviour

    public Camera camera;

    private Vector3 pos;
    private Quaternion targetRotation;
    private float rotationSpeed;

    void Start ()

        rotationSpeed = 3;


    void Update ()
        FaceMouse ();


    void FaceMouse ()

        pos = Input.mousePosition;
        pos.z = 10;
        pos = camera.ScreenToWorldPoint (pos);

        targetRotation = Quaternion.LookRotation (pos - transform.position);
        targetRotation.x = 0.0f;
        targetRotation.z = 0.0f;

        if (Vector3.Distance (pos, transform.position) > 1 && MouseMoved ()) {
            transform.rotation = Quaternion.Slerp (transform.rotation, targetRotation, Time.deltaTime * rotationSpeed);



What am I doing wrong? Thanks in advance!

I solved it, I had another script named Camera which in some way made problems.