function OpenLog: boolean;
begin
    result := false;
    try
        AssignFile(log, WLogFileName);
        if (FileExists(WLogFileName))and(not WLogClearOnStart) then begin
            Append(log);
            if FirstLine then begin
                WriteLn(log);
                FirstLine := false;
            end;
        end else begin
            WLogClearOnStart := false;
            Rewrite(log);
        end;
        result := true;
    finally

    end;
end;

function CloseLog: boolean;
begin
    result := false;
    try
        CloseFile(log);
        result := true;
    finally

    end;
end;

function AddToLog(const DT: TDateTime; const Text: string): boolean;

    function ClearText(const AText: string): String;
    var i: integer;
    begin
        result := AText;
        for I := 1 to Length(result) do
            if Ord(result[i]) < 32 then
                result[i] := '.';
    end;

begin
    result := false;
    try
        WriteLn(log, Format('%s : %s', [FormatDateTime('dd.mm.yyyy hh:nn:ss.zzz', DT), ClearText(Text)]));
        result := true;
    finally
    end;
end;

procedure TLogThread.WMErase(var Msg: TThreadMessage);
var f: File;
begin
    if FileOpened then
        FileOpened := not CloseLog;
    try
        if (not FileOpened) and (FileExists(WLogFileName)) then begin
            AssignFile(f, WLogFileName);
            Erase(f);
        end;
    finally

    end;
end;