// Downloaded From https://www.WiseStockTrader.com
dn = DateTime(); 
sd = SelectedValue( dn ); 

start = dn == sd; 

mp = (H+L)/2; 

PV = mp * V; 
CV = Cum( V ); 
VSS = CV - ValueWhen( start, CV ); 

denom = IIf( VSS == 0, 1, VSS ); 
num = Cum( PV ) - ValueWhen( start, Cum( PV ) ); 

M = IIf( BarsSince( start ), num/denom, mp ); 

Q1 = Param("Percentage Upper", 1, 0, 10, 0.01 ); 
Q2 = Param("Percentage Lower", 1, 0, 10, 0.01 ); 

Plot( C, Date() + " Close", colorBlack, styleBar ); 
Plot( M, "M" + _PARAM_VALUES(), colorBlue ); 
Plot( M * ( 1 + Q1 * 0.01 ), "Upper", colorGreen ); 
Plot( M * ( 1 - Q2 * 0.01 ),"Lower", colorRed );