procedure writeWorkLog(sqlstr: string);
var filev: TextFile;
  ss: string;
begin
  sqlstr:=DateTimeToStr(Now)+' Log: '+sqlstr;
  ss:='c:\ErpRunLog.txt';
  if FileExists(ss) then
  begin
    AssignFile(filev, ss);
    append(filev);
    writeln(filev, sqlstr);
  end else begin
    AssignFile(filev, ss);
    ReWrite(filev);
    writeln(filev, sqlstr);
  end;
  CloseFile(filev);
end;

procedure TForm1.btn1Click(Sender: TObject);
var
i: Integer;
begin
for i := 0 to 400 do
begin
writelog(mmo1, '日志信息' + inttostr(i));
end;
end;