pig scripts not working using amazon EMR

raw = LOAD ‘s3://xxxxxxxxx/*’ AS (name:chararray, year:float, occurrences:float, books:float);

B = GROUP raw BY name;

C = FOREACH B GENERATE B.name , SUM(B.occurrences)/SUM(B.books) AS average;

D = ORDER C BY average DESC;

E = LIMIT D 10;

STORE E INTO 's3://xxxxxx';