Egy szokásos program szerkezete

//----------------------------------------------------------------------------------
// Check.mqh
// The program is intended to be used as an example in MQL4 Tutorial.
//----------------------------------------------------------------------------- 1 --
// The function checking legality of the program used
// Inputs:
// - global variable 'Parol'
// - local constant "SuperBank"
// Returned values:
// true - if the conditions of use are met
// false - if the conditions of use are violated
//----------------------------------------------------------------------------- 2 --
extern int Parol=12345; // Password to work on a real account
//----------------------------------------------------------------------------- 3 --
bool Check() // Felhasználói függvény
 {
 if (IsDemo()==true) // Ha ez egy demó számla..
 return(true); // .. akkor nincs korlátozás
 if (AccountCompany()=="SuperBank") // For corporate clients..
 return(true); // ..no password is required
 int Key=AccountNumber()*2+1000001; // Calculate the key 
 if (Parol==Key) // If the password is true, then..
 return(true); // ..allow the user to work on a real account
 Inform(14); // Message about unauthorized use
 return(false); // Exit the user-defined function
 }
//----------------------------------------------------------------------------- 4 --

//----------------------------------------------------------------------------------------
// usualexpert.mq4
// The code should be used for educational purpose only.
//----------------------------------------------------------------------------------- 1 --
#property copyright "Copyright © Book, 2007"
#property link "http://AutoGraf.dp.ua"
//----------------------------------------------------------------------------------- 2 --
#include <stdlib.mqh>
#include <stderror.mqh>
#include <WinUser32.mqh>
//----------------------------------------------------------------------------------- 3 --
#include <Variables.mqh> // Description of variables 
#include <Check.mqh> // Checking legality of programs used
#include <Terminal.mqh> // Order accounting
#include <Events.mqh> // Event tracking function
#include <Inform.mqh> // Data function
#include <Trade.mqh> // Trade function
#include <Open_Ord.mqh> // Opening one order of the preset type
#include <Close_All.mqh> // Closing all orders of the preset type
#include <Tral_Stop.mqh> // StopLoss modification for all orders of the preset type
#include <Lot.mqh> // Calculation of the amount of lots
#include <Criterion.mqh> // Trading criteria
#include <Errors.mqh> // Error processing function
//----------------------------------------------------------------------------------- 4 --
int init() // Special function 'init'
 {
 Level_old=MarketInfo(Symbol(),MODE_STOPLEVEL );//Min. distance
 Terminal(); // Order accounting function 
 return; // Exit init() 
 }
//----------------------------------------------------------------------------------- 5 --
int start() // Special function 'start'
 {
 if(Check()==false) // If the usage conditions..
 return; // ..are not met, then exit
 PlaySound("tick.wav"); // At every tick
 Terminal(); // Order accounting function 
 Events(); // Information about events
 Trade(Criterion()); // Trade function
 Inform(0); // To change the color of objects
 return; // Exit start()
 }
//----------------------------------------------------------------------------------- 6 --
int deinit() // Special function deinit()
 {
 Inform(-1); // To delete objects
 return; // Exit deinit()
 }
//----------------------------------------------------------------------------------- 7 --

#include <Check.mqh> // Checking legality of programs used

#include <Variables.mqh> // Description of variables

//----------------------------------------------------------------------------
// Variables.mqh
// The code should be used for educational purpose only.
//----------------------------------------------------------------------- 1 --
// Description of global variables
extern double Lots = 0.0;// Amount of lots
extern int Percent = 0; // Allocated funds percentage
extern int StopLoss =100; // StopLoss for new orders (in points) 
extern int TakeProfit =40; // TakeProfit for new orders (in points)
extern int TralingStop=100; // TralingStop for market orders (in points)
//----------------------------------------------------------------------- 2 --
int 
 Level_new, // New value of the minimum distance
 Level_old, // Previous value of the minimum distance
 Mas_Tip[6]; // Order type array
 // [] order type: 0=B,1=S,2=BL,3=SL,4=BS,5=SS
//----------------------------------------------------------------------- 3 --
double
 Lots_New, // Amount of lots for new orders
 Mas_Ord_New[31][9], // Current order array ..
 Mas_Ord_Old[31][9]; // .. old order array
 // 1st index = order number in the list 
 // [][0] cannot be detected
 // [][1] order open price (abs. price value)
 // [][2] StopLoss of the order (abs. price value)
 // [][3] TakeProfit of the order (abs. price value)
 // [][4] order number 
 // [][5] order volume (abs. price value)
 // [][6] order type 0=B,1=S,2=BL,3=SL,4=BS,5=SS
 // [][7] Order magic number
 // [][8] 0/1 the fact of availability of comments
//----------------------------------------------------------------------- 4 --