public void Next3()
 {
     D3.SetActive(false);
     D4.SetActive(true);
     Nex3.SetActive(false);
     Nex4.SetActive(true);
 }
 public void Next2()
 {
     D2.SetActive(false);
     D3.SetActive(true);
     Nex2.SetActive(false);
     Nex3.SetActive(true);
 }