用全局變量，開倉前加上pos<1的判斷，收盤pos賦值為0，否則第二天也不開倉

VARIABLE:pos:=0;
IF HOLDING=0 AND TIME <145000 and TIME >090000 and pos<1 THEN BEGIN
   IF COND1 AND POS<2 THEN
    BUYSHORT(1,1,MARKET);
    POS:=POS+1;
    END
 if time=CLOSETIME(0) then pos:=0;