Private Sub Form_BeforeUpdate(Cancel As Integer)
	If DCount("*", "tblContacts", "lastName = """ & Me!txtLastName _
			& """ And firstName = """ & Me!txtFirstName & """") > 0 Then
		If MsgBox("There is already a user by that name in the table." & _
				" Do you wish to add it anyway?", vbYesNo) = vbNo Then
			Cancel = True
		End If
	End If
End Sub