Upgrade Indy9 to Indy10

I want to upgrade my application from Indy 9 to 10 with Delphi 2007. There is a lot of issues in this, I have read the in开发者_Go百科dy doc about changes but I still need advise. This won't compile as ReadString is not found.

vCmdHead := FTCPClient.ReadString(16);

where FTCPClient is of type TIdTCPClient. vCmdHead is a structure that contains a command as a string. What method could I use instead ?

      {$IFDEF INDY10}
      ALine := IdTCPClient.IOHandler.ReadString(16);
      {$ELSE}
      Aline := IdTCPClient.ReadString(16);
      {$ENDIF}

Something like this