Expert Advisor Programming by Andrew R. Young

Advanced Order Placement
When modifying orders, we must be sure that the values we are passing to the function are valid. For
example, the order must still be open – we cannot modify a closed order. When modifying pending
orders with the Price parameter, the order must not have already been filled – i.e. hit its order price.
The modified order price also must not be too close to the current Bid or Ask price. We should also
check to make sure that the stop loss and take profit are valid. We can do this using the price
verification routines that we will cover later in this chapter.
If we are not modifying a particular parameter, we must pass the original value to the
OrderModify() function. For example, if we are modifying only the stop loss for a pending order,
then we must retrieve the current order price and take profit using OrderSelect() , and pass those
values to the OrderModify() function.
If you attempt to modify an order without specifying any changed values, you'll get an error 1: "no
result". You should verify why your code is passing unchanged values to the function, but otherwise
this error is harmless and can be safely ignored.
Adding Stop Loss and Take Profit to an Existing Order
First, we need to verify that the order has been placed correctly. We do this by examining the return
value of the OrderSend() function, which is the ticket number of the order that was just placed. If
the order was not placed due to an error condition, the ticket number will be equal to -1.
Next, we use the OrderSelect() function to retrieve the information for the order that was just
placed. We will use the OrderOpenPrice(), OrderTakeProfit(), OrderStopLoss() and optionally
the OrderExpiration() functions when passing unchanged values to the OrderModify() function.
Finally, we'll use OrderModify() to add the stop loss and take profit to the order.
Here's an example where we set the stop loss and take profit for a buy order using the
OrderModify() function. We've moved the stop loss and take profit calculation after the
OrderSend() function, so that it is calculated before we modify the order:
int BuyTicket = OrderSend(Symbol(),OP_BUY,LotSize,Ask,UseSlippage,0,0,
"Buy Order",MagicNumber,0,Green);
if(BuyTicket > 0)
{
OrderSelect(BuyTicket,SELECT_BY_TICKET);
double OpenPrice = OrderOpenPrice();
if(StopLoss > 0) double BuyStopLoss = OpenPrice – (StopLoss * UsePoint);
if(TakeProfit > 0) double BuyTakeProfit = OpenPrice + (TakeProfit * UsePoint);
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