price slippage on pending order

1. A pending order becomes a market order; there will be slippage.
2. Remember the pending order price (perhaps a terminal variable) and compare to the opened price.
   

#property script_show_inputs

#include <MT4Orders.mqh> // https://www.mql5.com/en/code/16006

input long inTicket = 0; // Position Ticket

#define PRINT(A) Print(#A + " = " + (string)(A))

void OnStart()
{
  if (OrderSelect(inTicket, SELECT_BY_TICKET))
  {
    OrderPrint();
    
    PRINT(OrderOpenPrice());       
    PRINT(OrderOpenPriceRequest());

    PRINT(OrderClosePrice());
    PRINT(OrderClosePriceRequest());
    
    PRINT(OrderTicketID());
  }
}

Result.

#3880043 2022.06.13 23:29:22.299 buy 0.03 USDCHF 0.99832 0.00000 0.99631 2022.06.14 04:02:44.569 0.99632 -0.12 -0.01 -6.02 4;[+5] 4

OrderOpenPrice() = 0.99832
OrderOpenPriceRequest() = 0.99837

OrderClosePrice() = 0.99632
OrderClosePriceRequest() = 0.99631

OrderTicketID() = 10965077

Or use the script CustomReport.

Thank you. This is very helpful