Help me to disconnect connections without data

help me, my question is very noob :(

//s is TIdTCPServer
//-----------------------------------------
procedure TForm1.sConnect(AThread: TIdPeerThread); // this is line 1
var data:string;
begin
    data:=athread.Connection.readln();
    if data="login@username1@password1" then
       begin
          if checkacc(...) then
             begin
                  gotoACC();
                  exit; // line 10
            end;
       end;
    showmessage('here is line 13'); // this line called "line 13"
    athread.Connection.disconnect(); // this line called "line 14"
end;
//----------------------------------------

I want my server socket application will read data and check data when user connected, if username,password  correct, line 10 will exit the procedure , if not correct,line 13 will be executed and  line 14 will disconnect the current connection

:(( but when the user connected to my server appicaltion without writeln("login@user1@pass1") ,it just connected only, line 13 will never reached and the s.Threads.LockList.count will be increased by 1 until the user disconnected

someone can make a client app that can connect to my server frequently without disconnecting and in my app server , s.Threads.LockList.count will be bigger and bigger

experts, please help me, how can I detect that and disconnect a connection without data within event TIdTCPServer.OnConnect, i just want to keep the connections with data only

thank all.