🚀 go-pugleaf

I use TIdTime connect TimeServer,when i preset "host" Property at design ,it work.
But when i set "host " Property at program runing,it does't work,it can't connect TimeServer,

//---------------------------------------------------------------------------
void __fastcall TFormTimeClient::btnGetTimeClick(TObject *Sender)
{
    if(IdTime1->Connected())
        IdTime1->Disconnect();
    IdTime1->Host = cbxServer->Text;//"10.52.104.100";
    //IdTime1->Connect();
    //IdTime1->SyncTime();
    Memo1->Lines->Add(IdTime1->DateTime.FormatString("yyyy.mm.dd hh:nn:ss"));
}
//---------------------------------------------------------------------------
show error:
"Project TimeClient.exe raised exception class EIdSocketError with message 'Socket Error # 10061 Connection refused.'.Process stoped.Use Step or Run to continue."

How to use TIdTime ???