procedure TForm1.BitBtn1Click(Sender: TObject);
const  Count = 10;
var L,Lu,Ll: TLineSeries;
    Data,DataU,DataL : array of Double;
    i : integer;
begin
   SetLength(Data,Count);
   SetLength(DataU,Count);
   SetLength(DataL,Count);
   L := TLineSeries.Create(Self);
   Lu := TLineSeries.Create(Self);
   Lu.Stairs := True;
   Ll := TLineSeries.Create(Self);
   Ll.Stairs := True;
   L.ParentChart := Chart1;
   Lu.ParentChart := Chart1;
   Ll.ParentChart := Chart1;
   for i := 0 to Count-1 do begin
//     Data[i] :=
//     DataU[i] :=
//     DataL[i] :=
   end;
   L.AddArray(Data);
   Lu.AddArray(DataU);
   Ll.AddArray(DataL);
end;