HiLo modified for Amibroker (AFL)

_SECTION_BEGIN("HiLo modified");
K = Param("K",3,1,25,1,0);
per = Param("per",6,1,10,1);
filt = ATR(per)*k ; 

Lo = 0; 
Hi = H + 2*filt; 

for(i = 2; i < BarCount; i ++) 
{ 
   if(i == 2) trend[1] = 1; 


   if(trend[i-1] == 1) 
   { 
      LoN = C[i] - filt[i]; 
      if(LoN > Lo[i-1]) 
      { 
         Lo[i] = LoN; 
      } 
      else 
      { 
         Lo[i] = Lo[i-1]; 
      } 
      if(L[i] < Lo[i])    
      { 
         trend[i] = 0; 
         Hi[i] = L[i] + filt[i]; 
      } 
      else trend[i] = 1; 
   } 
   if(trend[i-1] == 0) 
   { 
      HiN = C[i] + filt[i]; 
      if(HiN < Hi[i-1]) 
      { 
         Hi[i] = HiN; 
      } 
      else 
      { 
         Hi[i] = Hi[i-1]; 
      } 
      if(H[i] > Hi[i]) 
      { 
         trend[i] = 1; 
         Lo[i] = H[i] - filt[i]; 
      } 
      else trend[i] = 0; 
   } 
} 

Hi = IIf(!trend, Hi, Null); 
Lo = IIf(trend, Lo, Null); 

UpDw=Flip( Hi, Lo );
Color = IIf(UpDw, colorRed, colorBlue); 

HiLoLine = IIf(UpDw, Hi, Lo); 


Plot(HiLoLine, "Hi Lo Line", Color, styleStaircase); 
_SECTION_END();