主题：以下内容是版主以前的一个模板，初学有点看不懂，请老师解读一下，特别是红色的部分。谢谢！

Global variable: hold=drawnull;

cc800988:=holding;//这句放在信号稳定的地方，

MA5:MA(CLOSE,5);

MA10:MA(CLOSE,10);

buycond:= CROSS(MA5,MA10);
sellcond:= CROSS(MA10,MA5);

drawtextex(1,1,800,0,'虚拟持仓为：'+numtostr(cc800988,0));//在图表上输入虚拟持仓以便监控
if not(islastbar) or workmode<>1 then exit;//最后周期，工作模式
xiadan800988:=cc800988-hold;

if xiadan800988>0.5 then begin
cang:=min(xiadan800988,abs(hold));
if hold<0 then begin
tsellshort(1,cang,mkt,0,0,'800988'),allowrepeat;
debugfile('D:\800988.txt',numtostr(hold,0)+' '+numtostr(cc800988,0)+' 平空 %.0f',cang);
end
cang:=xiadan800988+min(hold,0);
if cang>0 then begin
tbuy(1,cang,mkt,0,0,'800988'),allowrepeat;
debugfile('D:\800988.txt',numtostr(hold,0)+' '+numtostr(cc800988,0)+' 开多 %.0f',cang);
end
end
if xiadan800988<-0.5 then begin
cang:=min(abs(xiadan800988),abs(hold));
if hold>0 then begin
tsell(1,cang,mkt,0,0,'800988'),allowrepeat;
debugfile('D:\800988.txt',numtostr(hold,0)+' '+numtostr(cc800988,0)+' 平多 %.0f',cang);
end
cang:=abs(xiadan800988)-max(hold,0);
if cang>0 then begin
tbuyshort(1,cang,mkt,0,0,'800988'),allowrepeat;
debugfile('D:\800988.txt',numtostr(hold,0)+' '+numtostr(cc800988,0)+' 开空 %.0f',cang);
end
end
hold:=cc800988;      怎么在最后定义？不解