Audit Trail on an unbound form

Function AuditTrail()
On Error GoTo Err_Handler
    
    Dim MyForm As Form, C As Control, xName As String
    Set MyForm = Screen.ActiveForm
 
    'Set date and current user if form has been updated.
    MyForm!Updates = MyForm!Updates & Chr(13) & Chr(10) & _
    "Changes made on " & Now & " by " & CurrentUser() & ";"
 
    'If new record, record it in audit trail and exit sub.
    If MyForm.NewRecord = True Then
        MyForm!Updates = MyForm!Updates & Chr(13) & Chr(10) & _
        "New Record """
    End If
 
    'Check each data entry control for change and record old value of Control.
    For Each C In MyForm.Controls
        
    'Only check data entry type controls.
    Select Case C.ControlType
        Case acTextBox, acComboBox, acListBox, acOptionGroup
            ' Skip Updates field.
            If C.Name <> "Updates" Then
    
            ' If control was previously Null, record "previous value was blank."
                If IsNull(C.OldValue) Or C.OldValue = "" Then
               '     MyForm!Updates = MyForm!Updates & Chr(13) & _
               '     Chr(10) & C.Name & "--previous value was blank"
                    
                ' If control had previous value, record previous value.
                ElseIf IIf(IsNull(C.Value), "", C.Value) <> C.OldValue Then
                    MyForm!Updates = MyForm!Updates & Chr(13) & Chr(10) & _
                    "-" & C.Name & " changed from " & C.OldValue & " to " & C.Value
                End If
            End If
        End Select
    Next C
 
TryNextC:
    Exit Function
      
Err_Handler:
    If Err.Number <> 64535 Then
        MsgBox "Error #: " & Err.Number & vbCrLf & "Description: " & Err.Description
    End If
    Resume TryNextC
End Function