PriceInfo.mq4

#property strict
#property indicator_chart_window

int OnInit()
{
    return INIT_SUCCEEDED;
}

int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
{
    double ask = MarketInfo(_Symbol, MODE_ASK);
    double bid = MarketInfo(_Symbol, MODE_BID);

    Comment("ask = " + DoubleToString(ask, _Digits) + "\n" +
        "bid = " + DoubleToString(bid, _Digits) + "\n" +
        "close[0] = " + DoubleToString(close[0], _Digits) + "\n" +
        "Close[0] = " + DoubleToString(Close[0], _Digits));

    return rates_total;
}