#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 Aqua
#property indicator_color2 Aqua
//#property indicator_width1 5
//#property indicator_width2 5

extern int period = 8;

double vftop[];
double vfbot[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   IndicatorBuffers(2);
   SetIndexBuffer(0, vfbot);
   SetIndexStyle(0, DRAW_ARROW);
   SetIndexArrow(0, 117);
   SetIndexEmptyValue(0, 0);
   SetIndexBuffer(1, vftop);
   SetIndexStyle(1, DRAW_ARROW);
   SetIndexArrow(1, 117);
   SetIndexEmptyValue(1, 0);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   int    counted_bars=IndicatorCounted();
   int i = Bars - counted_bars;
   if(counted_bars == 0) i = Bars - period*2;
   int j = 0;
   double t1, t2;
   
   while(i >= 0)
   {
      t1 = Low[i];
      t2 = High[i];
      for(j = i+1; j < i + period; j++)
      {
         t1 = MathMax(t1, Low[j]);
         t2 = MathMin(t2, High[j]);
      }
      if(t1 <= t2)
      {
         vftop[i] = t2;
         vfbot[i] = t1;
      }
      i--;
   }
//----
   return(0);
}
//+------------------------------------------------------------------+