unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    BoldChk: TCheckBox;
    ItalicChk: TCheckBox;
    UnderlineChk: TCheckBox;

    procedure CheckClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}


procedure TForm1.CheckClick(Sender: TObject);
var style:TFontStyles;
begin

  style:=Label1.Font.Style;  

  with (Sender as TCheckBox) do begin

    if sender=BoldChk then
       if  Checked then style:=style+[fsBold]
       else style:=style-[fsBold];

    if sender=ItalicChk then
       if  Checked then style:=style+[fsItalic]
       else style:=style-[fsItalic];

    if sender=UnderlineChk then
       if  Checked then style:=style+[fsUnderline]
       else style:=style-[fsUnderline];
  end;

  Label1.Font.Style:=style;
end;

end.
