How to rotate the turret in accordance with enemy?

i have a game object with a script attached to it,i want to rotate it arround the z-axis,and make it continously point toward the enemy moving,currently my turret is rotating around z-axis but not pointing towards my enemy prefab generated.
here is my code.

    using UnityEngine;
    using System.Collections;

    public class TurretScript : MonoBehaviour {

private float zRotation = 0.0f;

void Update ()
	zRotation += 1;
	transform.eulerAngles = new Vector3(0, 0, zRotation);

This has been answered in your other question

No need to bring up the same question 3 times…