objective of this code

1. place all available symbols in marketwatch in mt4 in an array
2. loop through the array to heck buy/sell condition
3. take new position only in the symbol which does not exist in open orders list
4. take close decisions if buy/sell condition is false

i am completely new to mql4 so i have made certain mistakes, i need help in fixing these mistakes and making the code memory efficient

the code

#property copyright ""
#property link      ""
#property version   "1.00"
#property strict

double a;
double b;
double c;
double as;
double bs;
double cs;
bool cb=false;
bool sb=false;
bool aop=false;
bool buyCondition = false;
bool sellCondition = false;
int order=0;
bool check=false;
bool bop=false;
bool a2op=false;
bool a3op=false;
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- create timer
   EventSetTimer(60);
   
//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//--- destroy timer
   EventKillTimer();
   
  }
//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
//---
   
  }
//+------------------------------------------------------------------+
//| Timer function                                                   |
//+------------------------------------------------------------------+
void OnTimer()
  {
//---
   for(int i=0;i<SymbolsTotal(true);i++)
   {
      if (buyC(SymbolName(i,true))==true && BT(SymbolName(i,true))==false)
      {aop=OrderSend(SymbolName(i,true),OP_BUY,0.01,Ask,0,0,0,"",0,0,Green);}

      if (sellC(SymbolName(i,true))==true && BT(SymbolName(i,true))==false)
      {bop=OrderSend(SymbolName(i,true),OP_SELL,0.01,Bid,0,0,0,"",0,0,Green);}
      
      if (buyC(SymbolName(i,true))==false && BT(SymbolName(i,true))==true) closeOrd(SymbolName(i,true));

      if (sellC(SymbolName(i,true))==false && BT(SymbolName(i,true))==true) closeOrd(SymbolName(i,true));
      

   }
  }
//+------------------------------------------------------------------+
bool buyC(string s1)
{
   a = iClose(s1,0,0);
   b = iMA(s1,0,10,0,MODE_SMA,PRICE_CLOSE,0);
   c = iRSI(s1,0,14,PRICE_CLOSE,0);
   if (a > b && c > 50)
   buyCondition = true;
   return(buyCondition);
}

bool sellC(string s2)
{
   as = iClose(s2,0,0);
   bs = iMA(s2,0,10,0,MODE_SMA,PRICE_CLOSE,0);
   cs = iRSI(s2,0,14,PRICE_CLOSE,0);
   if (as < bs && cs < 50)
   sellCondition = true;
   return(sellCondition);
}

bool BT(string S)
{
   for(int x=0;x<SymbolsTotal(true);x++)
   {
      if(OrderSelect(x,MODE_TRADES) &&  (S == OrderSymbol()))
      check = true;
   }
      return(check);
}

void closeOrd(string symb)
{
   for(int Y=0;Y<SymbolsTotal(true);Y++)
   {
      if(OrderSelect(Y,MODE_TRADES) &&  (symb == OrderSymbol()))
      if (OrderType()==OP_BUY) 
      cb = OrderClose(OrderTicket(),OrderLots(),MarketInfo(symb,MODE_BID),Green);
      if (OrderType()==OP_SELL) 
      sb = OrderClose(OrderTicket(),OrderLots(),MarketInfo(symb,MODE_ASK),Green);
   }

}

i am completely new to mql4 so i have made certain mistakes, i need help in fixing these mistakes and making the code memory efficient