pig problem, can I do scalar assignments?

saveonerecord.pig

REGISTER 'socorro-toolbox-0.1-SNAPSHOT.jar'
REGISTER 'lib/akela-0.4-SNAPSHOT.jar'

SET pig.logfile saveonerecord.log;
SET default_parallel 2;
SET pig.tmpfilecompression true;
SET pig.tmpfilecompression.codec lzo;

uuid = '$uuid';
date = SUBSTRING(uuid, 30, 36);
hbaseid = SUBSTRING(uuid, 0, 1) + date + uuid;

raw = LOAD 'hbase://crash_reports' USING com.mozilla.pig.load.HBaseMultiScanLoader(date, date,
                                                                                   'yyMMdd',
                                                                                   'meta_data:json,processed_data:json',
                                                                                   'true') AS 
                                                                                   (k:bytearray, meta_json:chararray, processed_json:chararray);

f = FILTER raw BY k == uuid;

STORE f INTO 'saveonerecord-$uuid' USING PigStorage();