connecting oracle to codeigniter: oci_connect(): ORA-12541: TNS:no listener

Hi,
when i'm connecting oracle to codeigniter, i get this error:

Code:

oci_connect(): ORA-12541: TNS:no listener

.
this is the content of C:\oracle\network\ADMIN\tnsnames.ora

Code:

# tnsnames.ora Network Configuration File: C:\oracle\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

ORCL =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 10.74.14.161)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = orcl)
   )
 )

EXTPROC_CONNECTION_DATA =
 (DESCRIPTION =
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
   )
   (CONNECT_DATA =
     (SID = PLSExtProc)
     (PRESENTATION = RO)
   )
 )

where is the error? please help