N:=20;
boll:=MA(CLOSE,N);
UPPER:=BOLL+2*STD(CLOSE,N);
LOWER:=BOLL-2*STD(CLOSE,N);
DD:=UPPER-LOWER;
XG:crOSS(0.5,DD=LLV(DD,30));
N:=20;
boll:=MA(CLOSE,N);
UPPER:=BOLL+2*STD(CLOSE,N);
LOWER:=BOLL-2*STD(CLOSE,N);
DD:=UPPER-LOWER;
XG:crOSS(0.5,DD=LLV(DD,30));