主题：这段代码是计算开仓的均成本的，为什么全局变量失效？

VARIABLE:junjd=0;

hdjj:=holding,linethick0;
buy(close>ref(hhv(h,3),1) and count(v,0)>10  and holding>=0 and holding<10,1,LIMITR,o);
junjd:=(junjd*hdjj+enterprice*(holding-hdjj))/if(holding=0,1,holding);

hju:junjd,linethick0;