Customer Maintenance screen - Dynamics sl programmer please help

We have customized the Customer maintenance screen which is not working with 2018.  Apparently 2018 already has an update1 procedure.

Here is our old code

Private Sub Update1_OnUpdate(Level As Integer, InsertFlg As Integer, retval As Integer)
    Dim bxCFCustomerEx_temp As xCFCustomerEx

    If Level = 32001 Then
        holdIRN = ""
        If Trim(bxCFCustomerEx.ImageRefNbr) = "" Or Trim(bxCFCustomerEx.ImageRefNbr) = "<NEW>" Then
            holdIRN = GetNextImageRefNbr()
        End If
    End If

    If Level = LEVEL0 Then
        If holdIRN <> "" Then
            bxCFCustomerEx.ImageRefNbr = holdIRN
            Call DispFields("Form1", "xImageRefNbr")
        End If
        If CFCMSCustomerEXFound Then
            Call SUpdate1(csr_xCFCustomerEx, "xCFCustomerEx", bxCFCustomerEx, LenB(bxCFCustomerEx))
        Else
            Call SInsert1(csr_xCFCustomerEx, "xCFCustomerEx", bxCFCustomerEx, LenB(bxCFCustomerEx))
        End If
    End If
End Sub 

I created a button to save the user's input and copied the above code to the button click().  No I get this error

What do I have to change to get this button to work?