QUERY A PSQL DB USING CRONTAB

Hi to everyone i hope you can help me
Im doing a query in a database, but i want to use crontab to do it each
monday
There isn´t no problem when i run my script manually

]$ ./mdnimsi.sh
It generates to me a file
-rw-rw-r-- 1 swuser swuser 4446511 Sep 21 06:14 pttsubs20050921.txt--
but when i add mi script to the crontab, it genrates a file with 0 Kb , i
dont know why can you help me?
FECH=`/bin/date +%Y%m%d`
#Se hace la busqueda en la base de datos
cd /home/swuser/MDNIMSI
psql oampwms_4_1_0_0 -c "select
whlr_subscriber_profile.subscriber_id,whlr_mdn.m
dn from whlr_subscriber_profile,whlr_mdn where whlr_mdn.id =
whlr_subscriber_pro
file.mdn;" > pttsubs$FECH.txt

in crontab
10 * * * * /home/swuser/MDNIMSI/mdnimsi.sh
the output with crontab is
-rw-rw-r-- 1 swuser swuser 0 Sep 16 00:30 pttsubs050916.txt
~
Sigrid Yahaira Meneses Nielsen
tel cel 044 11 09 94 63