The name `playerTransform' does not exist in the current contextのエラー

Question

Assets/Script/EvasiveManeuver.cs(21,17): error CS0103: The name `playerTransform' does not exist in the current context
とエラーが出ます。

using UnityEngine;
using System.Collections;

public class EvasiveManeuver : MonoBehaviour {

	public float dodge;
	public float smoothing;
	public float tilt;
	public Vector2 startWait;
	public Vector2 maneuverTime;
	public Vector2 maneuverWait;
	public Boundary boundary;

	private float currentSpeed;
	private float targetManeuver;
	private Rigidbody rb;

	// Use this for initialization
	void Start () {
		rb = GetComponent <Rigidbody> ();
		playerTransform = GameObject.FindGameObjectWithTag ("Player").transform;
		currentSpeed = rb.velocity.z;
		StartCoroutine (Evade ());
	}

	IEnumerator Evade()
	{
		yield return new WaitForSeconds (Random.Range (startWait.x, startWait.y));

		while (true)
		{
			targetManeuver = Random.Range (1, dodge) * -Mathf.Sign (transform.position.x);
			yield return new WaitForSeconds (Random.Range (maneuverTime.x, maneuverTime.y));
			targetManeuver = 0;
			yield return new WaitForSeconds (Random.Range (maneuverWait.x, maneuverWait.y));
		}
	}

	void FixedUpdate ()
	{
		float newManeuver = Mathf.MoveTowards (rb.velocity.x, targetManeuver, Time.deltaTime * smoothing);
		rb.velocity = new Vector3 (newManeuver, 0.0f, currentSpeed);
		rb.position = new Vector3(
		
			Mathf.Clamp (rb.position.x, boundary.xMin, boundary.xMax),
			0.0f,
			Mathf.Clamp (rb.position.z, boundary.zMin, boundary.zMax)
		
		);
		rb.rotation = Quaternion.Euler (0.0f, 0.0f, rb.velocity.x * -tilt);
	}
	

}

とコードを書いたのですが

playerTransform = GameObject.FindGameObjectWithTag ("Player").transform;

の部分のどこが間違っているのでしょうか？

Answer 1

EvasiveManeuverクラスにplayerTransformというメンバ変数（フィールド)が見当たりません。
その名前のメンバ変数はMonoBehaviourに元々あるものではないので自分で宣言する必要があります。