Access Forms, VB Coding & Disabling Form Fields

Hi,
When using my Access Database in form mode, I'd like the fields "C1 Address", "C1 Postcode" & "C1 Home Phone" to be disabled when the checkbox "C1 same as YP?" is checked. The problem I'm facing is that the code I have works, but it then disables these fields on ALL records not just that specific record.

Here's what I have so far:

Private Sub C1_same_as_YP__AfterUpdate()
  If Not (Me.C1_same_as_YP_) = False Then
      Me.C1_Home_Phone.Enabled = False
      Me.C1_Address.Enabled = False
      Me.C1_Postcode.Enabled = False
  Else
      Me.C1_Home_Phone.Enabled = True
      Me.C1_Address.Enabled = True
      Me.C1_Postcode.Enabled = True
   End If
End Sub

Also once those fields have been disabled, I'd like them to clone information from fields "Home Address", "Post Code" & "Home Phone", so these details are displayed but editable.

Any help on these matters would be much appreciated.
Thanks in advance,
Crabbula