Deleting Records From A Table Through A Form Button Event

I have a FrmCadastro which updates my master table TblCadastro. Primary key of the TblCadastro is an auto numbered field named CADID.Fields CPF, NAME, FIN, NAT, TIP, MOT, and INSTREQ of the FrmCadastro are mandatory. My rule is that If any of these fields is null then the record cannot be saved (cannot be added into TblCadastro).

FrmCadastro has two distinct buttons, as follows: BtSave (to save either newly included record or changed record) and BtDelete (to delete a chosen record from my master table).To delete a record has not been a problem because under the click event of the BtDelete I use the following command lines to successfully eliminate an existing record (previously saved) from the TblCadastro:Dim numRecord As Integer

numRecord = Me.CADID
Dim SQL As String
DoCmd.SetWarnings False
SQL = "DELETE * FROM tblcadastro WHERE cadid = " & numRecord
DoCmd.RunSQL SQL
DoCmd.SetWarnings True

To save a complete record (properly filled in) has not been a problem either since the code takes care of that very well.When the user is in the process of adding a new record through the FrmCadastro two different user behaviors can take place:

1. Irregular entering - The user for some reason just give up saving the record (he decides to add the new record later, for instance) by selecting the option Save = No, or
2. Incomplete record - By mistake the user try to save an incomplete record (a record that shows any mandatory field as null).

I coded the following command lines under the click event of the BtSave to take care of deleting those records... BUT it does NOT work. The system reads each line of the code, find the record properly, close the form as expected, but the incomplete record STILL REMAINS in the TblCadastro. I do not understand why, since the code is pretty much the same of the one in the BtDelete.

Code:
Private Sub bt_save_Click()
If MsgBox("The record was changed. Do you want to save it?", vbQuestion + vbYesNo, Me.Caption) = vbYes Then
If MsgBox("WARNING! Incomplete record will be automatically deleted from database. If you did not fill in the fields CPF, NAME, FIN, NAT, TIP, MOT, and INSTREQ, the record will not be saved.", vbOKOnly, Me.Caption) Then
If Not IsNull(CPF) And Not IsNull(Name) And Not IsNull(FIN) And Not IsNull(NAT) And Not IsNull(TIP) And Not IsNull(MOT) And Not IsNull(INSTREQ) Then

[code]...

What should I code to exclude both the incomplete record and irregular entering thru the button Save (options Yes and No) ?