Look at mouse

Hello, I am looking for a script that makes the game object look at the mouse. I know there are many at Unity Answers, but my case is a bit different. The object I want to rotate is a child of another object, which is a rigidbody tank. This tank interacts with the terrain and objects, meaning it rotates, responds to gravity, has collisions, etc. Now the problem is that I want to rotate the turret on top of the tank, and with all the scripts I have tested, the turret ignores the rotation of the tank. Basicly, I want a script that only rotates the turret in the Y axis, but not change at all the x and z axis. Thank you!

using UnityEngine;
using System.Collections;

public class Look : MonoBehaviour {

    private Vector3 inputRotation;
    private Vector3 mousePlacement;
    private Vector3 screenCentre;

    void Update () {
    transform.rotation = Quaternion.LookRotation(inputRotation);

    void FindCrap () {
    screenCentre = new Vector3(Screen.width * 0.5f,0,Screen.height * 0.5f);
    mousePlacement = Input.mousePosition;
    mousePlacement.z = mousePlacement.y;
    mousePlacement.y = 0;
    inputRotation = mousePlacement - screenCentre;

That should give you what you need, incorporate it into your script attached to the to of the tank.