unity only rotate on y to folow mouse position code example

Example: unity rotate towards mouse

using UnityEngine;     using System.Collections;          public class SCR_mouseRotation : MonoBehaviour {                  void Update () {             Vector3 mousePos = new Vector3(Input.mousePosition.x, Input.mousePosition.z, 10);             Vector3 lookPos = Camera.main.ScreenToWorldPoint(mousePos);             lookPos = lookPos - transform.position;             float angle = Mathf.Atan2(lookPos.z, lookPos.x) * Mathf.Rad2Deg;             transform.rotation = Quaternion.AngleAxis(angle, Vector3.down); // Turns Right                 transform.rotation = Quaternion.AngleAxis(angle, Vector3.up); //Turns Left                      }     }