Hide the titlebar

Hide the titlebar.

Procedure TForm1.HideTitlebar;
var
Save : LongInt;
Begin
If BorderStyle=bsNone then Exit;
Save:=GetWindowLong(Handle,gwl_Style);
If (Save and ws_Caption)=ws_Caption then Begin
Case BorderStyle of
bsSingle,
bsSizeable : SetWindowLong(Handle,gwl_Style,Save and
(Not(ws_Caption)) or ws_border);
bsDialog : SetWindowLong(Handle,gwl_Style,Save and
(Not(ws_Caption)) or ds_modalframe or ws_dlgframe);
End;
Height:=Height-getSystemMetrics(sm_cyCaption);
Refresh;
End;
end;

And here is how we show it again:
Procedure TForm1.ShowTitlebar;
Var
Save : LongInt;
begin
If BorderStyle=bsNone then Exit;
Save:=GetWindowLong(Handle,gwl_Style);
If (Save and ws_Caption)<>ws_Caption then Begin
Case BorderStyle of
bsSingle,
bsSizeable : SetWindowLong(Handle,gwl_Style,Save or
ws_Caption or ws_border);
bsDialog : SetWindowLong(Handle,gwl_Style,Save or
ws_Caption or ds_modalframe or ws_dlgframe);
End;
Height:=Height+getSystemMetrics(sm_cyCaption);
Refresh;
End;
end;