MQL5 for loop check all positions if not open then in dobble lot size

[Pruthvirajsinh6212]

  //--- Include standard libraries
#include <Trade\AccountInfo.mqh>
#include <Trade\PositionInfo.mqh>
#include <Trade\SymbolInfo.mqh>
#include <Trade\Trade.mqh>

//--- Classes
CAccountInfo    AccountInfo;
CPositionInfo   PositionInfo;
CSymbolInfo     SymbolInfo;
CTrade          Trade_A;

input uint      MagicNumber      = 999;
input string    Symbol_A = "GBPUSD";  // Symbol

//START FROM HERE POSITION CREATE
double FirstBuy = 0.0;
double FirstSell = 0.0;

double ReBuy = 0;
double ReSell = 0;
double flag = 0;
double lastBuyEntryPrice = 0;
double lastSellEntryPrice = 0;

double BuyQty = 0.1;
double SellQty = 0.1;


//PROFIT BOOKING
double TakeProfit = 250 ;  // Take Profit (points)
double ReEntry = 150; // ReEntry Position (points)


void OnTick()
  {
   double Ask=NormalizeDouble(SymbolInfoDouble(Symbol_A,SYMBOL_ASK),_Digits); // Calculate the Ask Price
   double Bid=NormalizeDouble(SymbolInfoDouble(Symbol_A,SYMBOL_BID),_Digits);// Calculate the Bid Price



   if(FirstBuy == 0)
     {
      FirstBuy = 1;
      Trade_A.Buy(0.1,Symbol_A,0,0,(Ask + TakeProfit * _Point),"NEW BUY");
      lastBuyEntryPrice = (Ask + ReEntry * _Point);
     }

   if(FirstSell == 0)
     {
      FirstSell = 1;
      Trade_A.Sell(0.1,Symbol_A,0,0,(Bid - TakeProfit * _Point),"NEW Sell");
      lastSellEntryPrice = (Bid - ReEntry * _Point);
     }
}

i just open first buy and sell after we want make second buy and sell if take profit then dobble lot size buy