How to resolve ATR chart series issue

Question

Please help in attached application(Image Attached). Actually below plotted chart series is ATR( Average True Range). based on following formula (C#.NET).

chart1.DataManipulator.FinancialFormula(FinancialFormula.AverageTrueRange, txtPeriod.Text, "Series1:Y,Series1:Y2,Series1:Y4", "Series2:Y");

Series1 is first chart (top 1).

Series2 : neawly plotted series with above formula.

ATR once plotted we are not able to pass and refresh period with slider.

How to do that?