I want add horz scrollbar to a TListBox

I make
  SendMessage(lbContent.Handle, CB_SETHORIZONTALEXTENT, MaxInt, 0);
  ShowScrollBar(lbContent.Handle, SB_HORZ, True);

And now, the horz scrollbar are visible in my listbox, but when I click
on the button to scroll in my listbox the scrollbar became invisible
and my listbox are not scrolled

What I can do????

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