before insert and checkbox and subform

[a]

Thank You
I have subform and form (Master form)
In the subform before insert event I put this code :
====================
If Parent.checkbox1.Value = False Then
Cancel = True
Else
'
End If
============
If Parent.checkbox1.Value = 0 Then
Cancel = True
Else
'
End If
===================
If Me.Parent.checkbox1.Value = 0 Then
Cancel = True
Else
'
End If
========================
Why all this code not work correctly