Setting the cursor to be locked when a key is hit on keyboard

When you're in the game and hit the z button, it pops up the pause menu and a darkening background. The problem is that the cursor is disabled and locked while in game but i want it to be enabled and unlocked when they hit the pause button and then lock it when they resume the game. I've tried Cursor.LockState = CursorLockMode.None and Cursor.visible = true. But it doesn't seem to work. Below is the code for hitting the pause button. using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI;

 public class PauseGame : MonoBehaviour {
 
 public Transform pausebackground;
 
 public Transform pausemenu;
 
 // Update is called once per frame
 void Update () {
 if (Input.GetKeyDown(KeyCode.Z))
 {
 if (pausebackground.gameObject.activeInHierarchy == false && pausemenu.gameObject.activeInHierarchy == false)
 {
 Cursor.lockState = CursorLockMode.None;
 Cursor.visible = true;
 pausebackground.gameObject.SetActive(true);
 pausemenu.gameObject.SetActive(true);
 }else
 {
 Cursor.lockState = CursorLockMode.Locked;
 Cursor.visible = false;
 pausebackground.gameObject.SetActive(false);
 pausemenu.gameObject.SetActive(false);
 }
 }
 }
 }