如何添加新用户

Private Sub 登录系统_Click()
If IsNull(UserName) Then
  MsgBox "用户名不能为空，请重新选择！", vbExclamation + vbOKOnly, "提醒您！"
  Me.UserName.SetFocus
Else
If IsNull(password) Then
  MsgBox "注意，您忘了输入密码！", vbExclamation + vbOKOnly, "提醒您！"
  Me.password.SetFocus
Else
 If DLookup("Password", "UserList", "Username='" & UserName & "'") = [password] Then
   Me.Visible = False
    Me.password = Null
    MsgBox "登录成功！", vbExclamation, "提醒您"
    DoCmd.OpenForm "生产管理窗体"
    Else
MsgBox "您输入的密码有误，请重新输入，注意大小写！", vbExclamation + vbOKOnly, "提醒您！"
Me.password = Null
Me.password.SetFocus

End If
End If
End If

End Sub