Delphi 2009 Tcategorypanelgroup[4] Height

This example effect chart:

Code files:Unit Unit1;
Interface
Uses
Windows, Messages, sysutils, variants, Classes, Graphics, Controls, Forms,
Dialogs, Extctrls, Stdctrls, Comctrls;
Type
TForm1 = Class (Tform)
Categorypanelgroup1:tcategorypanelgroup;
Categorypanel1:tcategorypanel;
Categorypanel2:tcategorypanel;
Categorypanel3:tcategorypanel;
Pagescroller1:tpagescroller;
Button1:tbutton;
Button2:tbutton;
Button3:tbutton;
Button4:tbutton;
Procedure Formcreate (Sender:tobject);
Procedure Button1Click (Sender:tobject);
Procedure Button2click (Sender:tobject);
Procedure Button3click (Sender:tobject);
Procedure Button4click (Sender:tobject);
End
Var
Form1:tform1;
Implementation
{$R *.DFM}
Procedure Tform1.formcreate (Sender:tobject);
Begin
Categorypanel1.height: = clientheight Div 2;
Categorypanel2.height: = Categorypanel1.height;
Categorypanel3.height: = Categorypanel1.height;
Categorypanel1.caption: = ' CPanel1 ';
Categorypanel2.caption: = ' CPanel2 ';
Categorypanel3.caption: = ' CPanel3 ';
Categorypanelgroup1.gradientbasecolor: = Clyellow;
Categorypanelgroup1.gradientcolor: = clred;
Categorypanel1.color: = Clwhite;
Button1.caption: = ' categorypanelgroup1.headerheight + ';
Button2.caption: = ' categorypanelgroup1.headerheight-';
Button3.caption: = ' categorypanel1.height + ';
Button4.caption: = ' categorypanel1.height-';
End
Procedure Tform1.button1click (Sender:tobject);
Begin
Categorypanelgroup1.headerheight: = Categorypanelgroup1.headerheight + 2;
End
Procedure Tform1.button2click (Sender:tobject);
Begin
Categorypanelgroup1.headerheight: = categorypanelgroup1.headerheight-2;
End
Procedure Tform1.button3click (Sender:tobject);
Begin
Categorypanel1.height: = Categorypanel1.height + 10;
End
Procedure Tform1.button4click (Sender:tobject);
Begin
Categorypanel1.height: = categorypanel1.height-10;
End
End.