Can I call a procedure from OnExecute?

Can I call a procedure directly from OnExecute and will that procedure be
incorporated into
the thread that the client connection is in or must it be in a Synchronize()
or does it
depend on what is in that procedure (for example using VCL) .

Please consider the following:

----------------------------------------------
type
  TForm1 = class(TForm)
    IdTCPServer1: TIdTCPServer;
    procedure IdTCPServer1Execute(AThread: TIdPeerThread);
  private
  public
  end;

  procedure DoBlahBlah;

var
  Form1: TForm1;

implementation

procedure DoBlahBlah;
begin
    // DO Something Here
end;

procedure TForm1.IdTCPServer1Execute(AThread: TIdPeerThread);
var
    S : String;
begin
    S := AThread.Connection.ReadLn;
    If S = 'Blah-Blah' then
        DoBlahBlah;
end;
--------------------------------------------

Is this allowed?