674bool CalculateOrderVolume(double &volume)675  {676   volume=Lot;677   if(volume==0.0)678     {679      string currency=AccountInfoString(ACCOUNT_CURRENCY);680      double reference=ResolveBalanceStep();681682      // Preserve this substring-search direction; it is not an equality test.683      if(currency!="" && StringFind("JPY",currency)>=0) reference*=100.0;684      volume=(AccountInfoDouble(ACCOUNT_BALANCE)/reference)*percent;685      volume=MathMin(volume,SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MAX));686      volume=MathMax(volume,SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MIN));687     }688   if(Recovery) ApplyRecoveryVolume(volume);689   volume=NormalizeDouble(volume,2);690   volume=MathMin(volume,SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MAX));691   volume=MathMax(volume,SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MIN));692   double step=SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_STEP);693   if(step==0.0) return false;694   volume=MathFloor(volume/step)*step;695   double minimum=SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MIN);696   double maximum=SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_MAX);697   if(volume<minimum || volume>maximum) return false;698   step=SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_STEP);699   if(step==0.0 || MathAbs((int)MathRound(volume/step)*step-volume)>0.0000001) return false;700   double limit=SymbolInfoDouble(_Symbol,SYMBOL_VOLUME_LIMIT),used=0.0;701702   for(int index=PositionsTotal()-1;index>=0;--index)703      if(PositionGetTicket(index)!=0 && PositionGetString(POSITION_SYMBOL)==_Symbol)704         used+=PositionGetDouble(POSITION_VOLUME);705   if(limit>0.0 && volume>limit) volume=limit;706   for(int index=OrdersTotal()-1;index>=0;--index)707      if(OrderGetTicket(index)!=0 && OrderGetString(ORDER_SYMBOL)==_Symbol)708         used+=OrderGetDouble(ORDER_VOLUME_CURRENT);709   return limit<=0.0 || (limit-used)-volume>=0.0;710  }711712// Check required margin at the current price for the order side.713bool HasRequiredMargin(const ENUM_ORDER_TYPE side,const double volume)714  {715   MqlTick tick; if(!SymbolInfoTick(_Symbol,tick)) return false;716   double free_margin=AccountInfoDouble(ACCOUNT_MARGIN_FREE),required=0.0;717   double price=(side==ORDER_TYPE_SELL ? tick.bid : tick.ask);718   if(!OrderCalcMargin(side,_Symbol,volume,price,required))719     {720      Print("Error in CheckMoneyForTrade code=",GetLastError()); return false;721     }722   if(required>free_margin)723     {