dynamic lotsize calculation mql5 , mt5

//+------------------------------------------------------------------+

//|                                         test dynamic posiion.mq5 |

//|                                  Copyright 2023, MetaQuotes Ltd. |

//|                                             https://www.mql5.com |

//+------------------------------------------------------------------+

#include <Trade\Trade.mqh>

CTrade trade;

#property copyright "Copyright 2023, MetaQuotes Ltd."

#property link      "https://www.mql5.com"

#property version   "1.00"

double balance,lotsize,ask;

//+------------------------------------------------------------------+

//| Expert initialization function                                   |

//+------------------------------------------------------------------+

int OnInit()

  {

//---

   

//---

   return(INIT_SUCCEEDED);

  }

//+------------------------------------------------------------------+

//| Expert deinitialization function                                 |

//+------------------------------------------------------------------+

void OnDeinit(const int reason)

  {

//---

   

  }

//+------------------------------------------------------------------+

//| Expert tick function                                             |

//+------------------------------------------------------------------+

void OnTick()

  {

   

  

  }

//+------------------------------------------------------------------+

double callots(double risk, double sl_val)

{

   double ticksize=SymbolInfoDouble(Symbol(),SYMBOL_TRADE_TICK_SIZE);

   double tickval=SymbolInfoDouble(Symbol(),SYMBOL_TRADE_TICK_VALUE);

   double lotstep = SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_STEP);

   

   if (ticksize==0||tickval==0||lotstep==0){ return 0}

   

   double riskmoney=AccountInfoDouble(ACCOUNT_BALANCE)*risk/100;

   double moneyperlot= (sl_val/ticksize)*tickval*  lotstep    ;

   

   double lots = MathFloor(riskmoney/moneyperlot ) * lotstep;

   

   

   return lots;

   

   

}