請協助看看我的選股"連n日漲跌幅小於2%"的程式錯在哪?挑不出股票很奇怪???

inputs:length(5,"連續天數");

var:n(0),i(1);

array:numarray1[](0),numarray2[](0);

Array_SetMaxIndex(numarray1,length);

Array_SetMaxIndex(numarray2,length);

for i=1 to length begin

numarray1[i]=(getField("收盤價", "D")[i-1]-getField("收盤價", "D")[i])/getField("收盤價", "D")[i];//(c[i-1]-c[i])/c[i]

numarray2[i]=absvalue(numarray1[i]);

if numarray2[i]< 0.02 then n=n+1;

end;

if n=length then ret=1;