请帮助编写高低点限时显示
1、当日有效；
2、只显示前30分钟.
谢谢！
指标：
GG:HHV(H,10);
DD:LLV(L,10);
runmode:0;
h1:=HHV(H,10);
l1:=LLV(L,10);
if time0<=timetot0(opentime(1))+60*30 then GG:h1;
if time0<=timetot0(opentime(1))+60*30 then DD:l1;
runmode:0;
h1:=HHV(H,10);
l1:=LLV(L,10);
if time0<=timetot0(opentime(1))+60*30 then GG:h1;
if time0<=timetot0(opentime(1))+60*30 then DD:l1;
if time>opentime(2) and time0<=timetot0(opentime(2))+60*30 then GG1:h1;
if time>opentime(2) and time0<=timetot0(opentime(2))+60*30 then DD1:l1;