請教如何撰寫在台指期1分K上畫出昨天夜盤高低點及高低點平均價的水平線?

if time = 150000 then begin

    value1 = high;

    value2 = low;

    value3 = currentBar;

    end

else if time < 050000 then begin

    if high > value1 then value1 = high;

    if low < value2 then value2 = low;

    if time = 045900 then value4 = currentBar;

    end;

if time = 050000 then begin 

    plotline(1, value3, value1, value4, value1, add:=1);

    plotline(2, value3, value2, value4, value2, add:=1);

    end;

圖上無法標示出來,請教如何修改 謝謝!