SAP TO R/3 Connection

Hello Experts,

I have to establish a connection between SAP R/3 and a Oracle Database. Both are located on different Servers.

i have made these entries in the respective fields.

Database Connection: TST


Username: Usrnam


Connection Information : ORCL

Here ORCL is the name of the component in Oracle File named TNS.TXT

Bt still thrs no connectivity. When i am running the tcode DB6COCKPIT . It is giving me this message.

"No systems are enabled or configured."

"Check the system registration."

My ECC version is 5.0 and its on Linux Platform and even my oracle Server is on Linux Platform.Please Help