[traderdoc]

flag = false;
for (int i = OrdersTotal()-1; i >= 0; i--) {  
   if (OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) {
      if (OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber) {
         if (OrderType() == OP_BUY || OrderType() == OP_SELL) {
            flag = true;
         }
      }
   }
}
if (!flag) {
   //ggf. Action
}

traderdoc