Willy Bands

Reverse engineered Willy21Ema13 to show (on chart) the levels price would have to reach to be overbought/oversold given recent price history.
By default it only shows the Williams%R with length 21.
If you change the settings it will do the same for the Ema13 of the Willy21, however because the ema is "harder" to breach, the lines are much farther away and looks really obnoxious on chart.