procedure TMainForm.FTPDownload(str, strTo: string);
var
  Stream: TFileStream;
  strFrom: string;
  sr: TSearchRec;
begin
  if FileExists(strTo) then
  begin
    FindFirst(strTo, faAnyFile, sr);
    if sr.size<> idFTP1.size(strFrom) then
    begin
      if Application.MessageBox('文件存在,继续下载吗?', '注意', MB_YESNO) = idYes then
      begin
        if idFTP1.Connected then
        begin
          Stream := TFileStream.Create(strTo, fmOpenWrite);
          Stream.Seek(0, soFromEnd);
          idFTP1.SendCmd(Format('REST %d', [sr.Size]));
          try
            try
              idFTP1.Get(strFrom, Stream);
             //出现错误:提示invalid number of parameters
            except
            end;
          finally
            Stream.Free;
          end;
        end;
      end;
    end;
  end;
请问如何修改呢?谁能把CONNECT后面的几句是什么意思说清楚呢?
谢谢