unit MainForm;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

const
  UM_CONNECT = WM_USER + 1;

type
  TfrmMain = class(TForm)
    lblConnections: TLabel;
  private
    { Private declarations }
    FConnections: Integer;
    procedure UpdateConnections;
    procedure UMConnect(var Msg: TMessage); message UM_CONNECT;
  public
    { Public declarations }
  end;

var
  frmMain: TfrmMain;

implementation

{$R *.dfm}

{ TfrmMain }

procedure TfrmMain.UMConnect(var Msg: TMessage);
begin
  FConnections := FConnections + Msg.WParam;
  UpdateConnections;
end;

procedure TfrmMain.UpdateConnections;
begin
  if FConnections = 1 then
    lblConnections.Caption := '1 connection'
  else
    lblConnections.Caption := IntToStr(FConnections) + ' connections';
end;

end.