Кто знает подскажите пожалуйста, почему при закрытии моего приложения появляется ошибка типа Invalid pointer opration и как избавится от нее.
Ниже привожу код DLL фрагмент программы вызивающей функцию

library fvigr;

{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }

uses
SysUtils,Messages, Variants,Windows,Controls,
Classes;

{$R *.res}
function StrToOem(const AnsiStr: string): string;stdcall;
{$IFNDEF WIN32}
var
Src, Dest: array[0..255] of Char;
{$ENDIF}
begin
SetLength(Result, Length(AnsiStr));
if Length(Result) > 0 then
{$IFDEF WIN32}
AnsiToOem(PChar(AnsiStr), PChar(Result));
{$ELSE}
begin
StrPCopy(Src, AnsiStr);
AnsiToOem(Src, Dest);
Result := StrPas(Dest);
end;
{$ENDIF}
end;

function OemToAnsiStr(const OemStr: string): string;stdcall;
begin
SetLength(Result, Length(OemStr));
if Length(Result) > 0 then
{$IFDEF WIN32}
OemToCharBuff(PChar(OemStr), PChar(Result), Length(Result));

{$ELSE}
OemToAnsiBuff(@OemStr[1], @Result[1], Length(Result)); {$ENDIF}
end;


function intform (s:string):boolean;stdcall;
const
digit=['0','1','2','3','4','5','6','7','8','9'];
begin
result:=(length(s)=1) and
(s[1] in digit);
end;

function typnum (tp:string):boolean;stdcall;
const
digit=['0','1','2','3','4','5','6','7','8','9'];
begin
result:= (length(tp)=2) and
(tp[1] in digit)and
(tp[2] in digit);
end;

function ValidDate(const d: Tdate): Boolean;stdcall;
BEGIN
Result := True;
try
Datetostr(d);
except
ON EConvertError DO

Result := False;
end;
END;


function SqlUpdate(Values : string; TablName : string;
ColNames : string; WhereClause : string) : string;stdcall;
const
// Возврат и перевод каретки
CrLf = #13#10;
var
RetVar: string;
//i : integer;
begin
RetVar := 'update ' + tablname + ' set ' + CrLf;
RetVar := RetVar + ColNames + '=' + values + ' ';
Delete(RetVar,length(RetVar),1);
RetVar := RetVar + CrLf + 'where '+ colnames+'='+ WhereClause;

Result := RetVar;

end;
exports
SqlUpdate,
intform,
typnum,
ValidDate,
OemToAnsiStr,
StrToOem;

end.

программа

unit tecoper;

interface
uses
sharemem,Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, DB, DBTables, StdCtrls, DbPrgrss,roz;

type
Ttoper = class(TForm)
Button1: TButton;
Query1: TQuery;
DataSource1: TDataSource;
DBProgress1: TDBProgress;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public

{ Public declarations }
end;

var
toper: Ttoper;
Year, Month, Day:word;
implementation

{$R *.dfm}


procedure Ttoper.Button1Click(Sender: TObject);
var
i:integer;
old_cod:array [1..13] of string;
new_cod:array [1..13] of string;
old_num:array [1..13] of string;
new_num:array [1..13] of string;
begin
old_cod[1]:='01';
old_cod[2]:='02';
old_cod[3]:='03';
old_cod[4]:='05';
old_cod[5]:='43';
old_cod[6]:='23';
old_cod[7]:='32';
old_cod[8]:='33';
old_cod[9]:='34';
old_cod[10]:='36';
old_cod[11]:='35';
old_cod[12]:='99';
old_cod[13]:='37';
new_cod[1]:='11';
new_cod[2]:='12';
new_cod[3]:='12';
new_cod[4]:='41';
new_cod[5]:='13';
new_cod[6]:='44';
new_cod[7]:='61';
new_cod[8]:='67';
new_cod[9]:='62';
new_cod[10]:='63';
new_cod[11]:='65';
new_cod[12]:='47';
new_cod[13]:='61';
for i:=1 to 13 do
begin
query1.sql.Clear;
query1.SQL.Text:=SqlUpdate(ansiquotedstr(new_cod ,''''),'amt','c_tec_oper', ansiquotedstr(old_cod,''''));
query1.ExecSQL;
end;
showmessage('Конвертирование техопераций завершено');

end;
end.