Необходимо немного изменить программу

unit Stroki;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Buttons, StdCtrls;
 
type
  TMain_Form = class(TForm)
    Btn_zamena: TButton;
    Lbl1: TLabel;
    BitBtn1: TBitBtn;
    LBox_red: TListBox;
    CmbBox_stroki: TComboBox;
    Lbl2: TLabel;
    procedure Btn_zamenaClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Main_Form: TMain_Form;
implementation
 
{$R *.dfm}
function propisnble(s:string):string;//замена букв
var j,n:integer;
begin
   j:=1;
    n:=length(s);
    s[j]:=upcase(s[1]);
while j<=n do begin
j:=j+1;
if s[j-1]=' ' then s[j]:=Upcase(s[j]);
end;
propisnble:=s;
 
end;
 
procedure TMain_Form.Btn_zamenaClick(Sender: TObject);
begin
   if (CmbBox_stroki.Text='') then
   else LBox_red.Items[0]:=propisnble(CmbBox_stroki.Text);
end;
 
procedure TMain_Form.FormCreate(Sender: TObject);
begin
   CmbBox_stroki.ItemIndex:=0;
end;
 
end.