Oracle Database Discussions

I am unable to connect from my client side to the database I am getting ORA-12514:TNS:listener could not resolve SERVICE_NAME , i am trying to access the database through the Oracle enterprise manager console at the client side.

Client OS: XP
Server OS: IBM AIX
Oracle Version: Oracle9i Enterprise Edition Release 9.2.0.7.0 - 64bit Production
Global Databasename:*ORA7*
SID:*ora7*(small letters)(found by select instance_name from v$instance)
Host Name:*hwhlr10*

#I got the two files, tnsnames.ora and listener.ora but sqlnet.ora is unavailable at this directory /opt/hlr/tools/crtdb
#i did a tnsping ora7 i got this error TNS-03505: Failed to resolve name
#i did oracle> sqlplus username/password@ora7 and i got this error ORA-12154: TNS:could not resolve service name


TNSNAMES.ORA
=========================
root@hwhlr_ph1 # cat tnsnames.ora
# TNSNAMES.ORA Network Configuration File: /opt/oracle/product/9.2/network/admin
/tnsnames.ora
# Generated by Oracle configuration tools.

#EXTPROC_CONNECTION_DATA =
# (DESCRIPTION =
# (ADDRESS_LIST =
# (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
# )
# (CONNECT_DATA =
# (SID = PLSExtProc)
# (PRESENTATION = RO)
# )
# )

orarman =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = hwhlr10)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = rman)
)
)
===========================
LISTENER.ORA
===========================
# LISTENER.ORA Network Configuration File: /opt/oracle/product/9.2/network/admin
/listener.ora
# Generated by Oracle configuration tools.

#LISTENER =
# (DESCRIPTION_LIST =
# (DESCRIPTION =
# (ADDRESS_LIST =
# (ADDRESS = (PROTOCOL = TCP)(HOST = 10.71.10.50)(PORT = 1521))
# )
# (ADDRESS_LIST =
# (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
# )
# )
# )
#
#SID_LIST_LISTENER =
#(SID_LIST =
# (SID_DESC =
# (SID_NAME = PLSExtProc)
# (ORACLE_HOME = /opt/oracle/product/9.2)
# (PROGRAM = extproc)
# )
#)


SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = rman)
(ORACLE_HOME = /opt/oracle/product/9.2)
)
)

LISTENER =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = hwhlr10)(PORT = 1521))
)
============================================

I am kindly requesting u to help me on this error. Many Thanks