DB2 ODBC connectivity problem in RHEL5 32 bit

Hi,
I installed Db2 9.7 on RHEL5 32bit .
Instance Name is db2inst1 amd in that i created database as mydb.
I exported env variables for
classpath ,db2dir,db2instance
LD_LIBRARY_PATH ,PATH ,ODBC, ODBCHOME ,ODBCINI
My application needs ODBC connectivity and so I modified odbc.ini file .
Following is the configuration for the same :

[DB2_TEST]
Driver=/home/db2inst1/sqllib/lib32/libdb2.so
Description=DB2 9.7 Driver
SERVER=localhost
PORT=50000
USER=db2inst1
Password=abcd1234
Database=MYDB
OPTION=3
SOCKET=

when I execute , getting this error
isql -v db2_test db2inst1 abcd1234
[S1009][unixODBC][IBM][CLI Driver] CLI0124E Invalid argument value. SQLSTATE=S1009
[ISQL]ERROR: Could not SQLConnect

Kindly Help