Php 4.3 & Oracle 9: Connecting to two different oracle Database

[phpaliens322]

What is the standard method to configure two oracle databases?
For example: I have one production & a development environment

1. Do i need to export two sids?
2. Production Enviorment working fine, how do I add the development sid?

tnsnames.ora :
dev =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.220.224)(PORT = 1521))
(CONNECT_DATA =
(SID = dev)
)
)

production =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.60.60.230)(PORT = 1521))
(CONNECT_DATA =
(SID = prod)
)
)

Thanks,

PhpAliens322