Expert Advisor Programming by Andrew R. Young

Advanced Order Placement
Putting It All Together
We're going to add all of the features we've covered in this section to the simple expert advisor we
created on page 36. We'll be adding order modification, stop level verification, trade context
checking, predefined variable refreshing and lot size verification to our EA. Here is our file, starting at
the beginning:
#property copyright "Andrew Young"
#include
// External variables
extern bool DynamicLotSize = true;
extern double EquityPercent = 2;
extern double FixedLotSize = 0.1;
extern double StopLoss = 50;
extern double TakeProfit = 100;
extern int Slippage = 5;
extern int MagicNumber = 123;
extern int FastMAPeriod = 10;
extern int SlowMAPeriod = 20;
// Global variables
int BuyTicket;
int SellTicket;
double UsePoint;
int UseSlippage;
int ErrorCode;
We've added the #include statement for the stdlib.mqh file that contains the
ErrorDescription() function for our error handling routines. We've added three external variables
for the lot sizing, and a global variable for the error code.
The following code goes at the beginning of the start() function:
// Moving averages
double FastMA = iMA(NULL,0,FastMAPeriod,0,0,0,0);
double SlowMA = iMA(NULL,0,SlowMAPeriod,0,0,0,0);
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