rzgroupbar中怎么判断用户选择的是哪个group

rzgroupbar中如何判断用户选择的是哪个group?
用户通过右键菜单进行删除group操作，我现在不知道如何判断用户所要删除的是那个group?

[解决办法]
好象不太好控制,
可以通过鼠标坐标是否在某Group的区域内，
或者用一变量来记录某个group曾获得过焦点
[解决办法]

Delphi(Pascal) code

这样可以不?unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, RzGroupBar, Menus;type  TForm1 = class(TForm)    RzGroupBar1: TRzGroupBar;    RzGroup1: TRzGroup;    RzGroup2: TRzGroup;    PopupMenu1: TPopupMenu;    MIDelete: TMenuItem;    procedure RzGroup1MouseDown(Sender: TObject; Button: TMouseButton;      Shift: TShiftState; X, Y: Integer);    procedure RzGroup2MouseDown(Sender: TObject; Button: TMouseButton;      Shift: TShiftState; X, Y: Integer);    procedure MIDeleteClick(Sender: TObject);  private    { Private declarations }    curRzGroup:TRzGroup;  public    { Public declarations }  end;var  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.RzGroup1MouseDown(Sender: TObject; Button: TMouseButton;  Shift: TShiftState; X, Y: Integer);begin  curRzGroup:=TRzGroup(Sender);end;procedure TForm1.RzGroup2MouseDown(Sender: TObject; Button: TMouseButton;  Shift: TShiftState; X, Y: Integer);begin  curRzGroup:=TRzGroup(Sender);end;procedure TForm1.MIDeleteClick(Sender: TObject);begin  RzGroupBar1.RemoveGroup( curRzGroup );end;end.