procedure TForm1.Button1Click(Sender: TObject);
Var
   X,I,Y:integer;
  cText:String;
  bNext:Boolean;
  T : TTabSheet;
begin

 For I:=0 to Self.DriveComboBox1.Items.Count-1 do
   begin
     cText:=DrivecomboBox1.Items.Strings[i];
     bNext:=True;
     for Y:=0 to Self.PageControl1.PageCount-1 do
        begin
           IF Self.PageControl1.Pages[i].Caption=cText then bNext:=False;
          end;
      IF bNext then
        begin
          with T do
            begin
               T:=TTabSheet.Create(Self.PageControl1);
               T.Caption:=cText;
                PageControl:=Self.PageControl1; 
               bNext:=False;
              end;
         end;
    end;

    repeat
      begin
     for Y:=0 to Self.PageControl1.PageCount-1 do
      begin
        cText:=Self.PageControl1.Pages[Y].Caption;
        bNext:=False;
        For I:=0 to Self.DriveComboBox1.Items.Count-1 do
          begin
             IF Self.DriveComboBox1.Items.Strings[i]=cText then
                begin
                   bNext:=True;
                end;
            end;
          IF Not bNext then
             begin
               Self.PageControl1.Pages[Y].Destroy;
               Break;
               end;
        end; end;
      Until PageControl1.PageCount=Self.DriveComboBox1.Items.Count;