追踪止损怎么自动移动？

// 追踪止损（移动止损）
double trailingStop = 500;  // 追踪距离，单位点

void OnTick() {
    for(int i = OrdersTotal() - 1; i >= 0; i--) {
        ulong ticket = OrderGetTicket(i);
        if(OrderSelect(ticket)) {
            if(OrderGetString(ORDER_SYMBOL) != Symbol()) continue;
            
            double openPrice = OrderGetDouble(ORDER_OPENPRICE);
            double currentSL = OrderGetDouble(ORDER_SL);
            int type = OrderGetInteger(ORDER_TYPE);
            
            if(type == OP_BUY) {
                double newSL = Bid - trailingStop * Point;
                // 如果新止损比当前止损高，就上移
                if(newSL > currentSL && Bid - openPrice > trailingStop * Point) {
                    OrderModify(ticket, openPrice, newSL, OrderGetDouble(ORDER_TP), 0, clrBlue);
                    Print("买单 #", ticket, " 追踪止损上移到：", DoubleToString(newSL, Digits));
                }
            } else if(type == OP_SELL) {
                double newSL = Ask + trailingStop * Point;
                // 如果新止损比当前止损低，就下移
                if(newSL < currentSL || currentSL == 0) {
                    if(openPrice - Ask > trailingStop * Point) {
                        OrderModify(ticket, openPrice, newSL, OrderGetDouble(ORDER_TP), 0, clrRed);
                        Print("卖单 #", ticket, " 追踪止损下移到：", DoubleToString(newSL, Digits));
                    }
                }
            }
        }
    }
}