start your listener. from the command prompt issue 
lsnrctl start -- will start your default listener
lsnrctl start < listener_name > -- will start the specific listener

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = itloaner1)(PORT = 1521))
      )
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
      )
    )
  )

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = C:OracleOra81)
      (PROGRAM = extproc)
    )
    (SID_DESC =
      (GLOBAL_DBNAME = local)
      (ORACLE_HOME = C:OracleOra81)
      (SID_NAME = local)
    )
    (SID_DESC =
      (GLOBAL_DBNAME = clone)
      (ORACLE_HOME = C:OracleOra81)
      (SID_NAME = clone)
    )
    (SID_DESC =
      (GLOBAL_DBNAME = sample)
      (ORACLE_HOME = C:OracleOra81)
      (SID_NAME = sample)
    )
  )

nothing is wrong.
everything is behaving as expected.

1. oracle and forms should be in different ORACLE_HOME.
   Any oracle client ( sqlplus or forms or reports or anyother tools like discoverer) uses its own tnsnames.ora to connect to oracle.
   so every $ORACLE_HOME/network/admin/tnsnames.ora in every home should have the same entries.

2. if you have an oracle client and oracle server,
   in the same machine, you no need to have a connect string.
   you can connect with username/passcode.
   if you have multiple databases in the same machine need to set oracle_sid every time to connect to a particular database. to avoid that, we use connectstrings so that
    username/passcode@string1 connects to db1
    usernmae/passcode@string2 connnects to db2
but username/passcode      will connect to whatver database is left as default, defined by oracle_sid.
if you use connectstring, then u should have proper entries in your tnsnames.ora and have a listener properly configured.
  
3. ODBC for oracle uses tnsconnecstring.
   it will work fine>~