idftp连接服务器被拒绝，请教！！

我的代码
procedure Tconnectionform.Button1Click(Sender: TObject);
var
LS:TstringList;
begin

with IdFTP1 do try
Username :=edit1.text;
Password :=edit2.text;
Host :=edit3.text;
passive:=true;
Connect;
finally
end;
LS := TStringList.Create;
IdFTP1.TransferType:=ftASCII;

CurrentDirEdit.Text := IdFTP1.RetrieveCurrentDir;

DirectoryListBox.Items.Clear;

IdFTP1.List(LS);

DirectoryListBox.Items.Assign(LS);
end;
报错socket error #10061 connection refused.怎么回事，搞了好半天了，这点代码都通不过，用别的ftp软件能够正常登陆
谢谢各位！！