declare upper;
input length = {default “2”, “3”};
input ChartBubblesON = Yes;
input LinesON = Yes;

plot data;
rec top;
rec bot;
def index;

switch (length) {
    case “2”:
        index = 2;
        data= If !ChartBubblesON then
            Double.NaN else if Low < Low[1] && Low < Low[-1] && Low < Low[2] && Low < Low[-2] then
                Low else if High > High[1] && High > High[-1] && High > High[2] && High > High[-2] then
                    High else Double.NaN;
        top = if High > High[1] && High > High[-1] && High > High[2] && High > High[-2] then High else top[1];
        bot = if Low < Low[1] && Low < Low[-1] && Low < Low[2] && Low < Low[-2] then Low else bot[1];
    case “3”:
        index = 3;
        data = If !ChartBubblesON then
            Double.NaN else if Low < Low[1] && Low < Low[-1] && Low < Low[2] && Low < Low[-2] && Low < Low[3] && Low < Low[-3] then
                Low else if High > High[1] && High > High[-1] && High > High[2] && High > High[-2] && High > High[3] && High > High[-3] then
                    High else Double.NaN;
        top = if High > High[1] && High > High[-1] && High > High[2] && High > High[-2] && High > High[3] && High > High[-3] then High else top[1];
        bot = if Low < Low[1] && Low < Low[-1] && Low < Low[2] && Low < Low[-2] && Low < Low[3] && Low < Low[-3] then Low else bot[1];
}

Data.SetPaintingStrategy(PaintingStrategy.points);
Data.SetLineWeight(1);
Data.SetDefaultColor(color.yellow);
Data.HideBubble();
AddChartBubble(1, Data, concat(“”, data), color.white);

plot topline = if !LinesOn then Double.NaN else top;
topline.SetLineWeight(1);
topline.SetDefaultColor(color.yellow);
topline.SetPaintingStrategy(PaintingStrategy.dashes);
plot bottomline = if !LinesOn then Double.NaN else bot;
bottomline.SetLineWeight(1);
bottomline.SetDefaultColor(color.yellow);
bottomline.SetPaintingStrategy(PaintingStrategy.dashes);
Alert(ChartBubblesON and !IsNaN(data[index]), "Bubble Alert", Alert.BAR, Sound.RING);