Connecting to external database using ABAP

Hello All,

I am trying to connect to an external oracle database within the same network by doing the following..

- I setup the database connection using transaction code DMCO.

- in SE38 i used the following statement to connect to the database.

PARAMETERS dbs TYPE dbcon-con_name.

     EXEC SQL.
        CONNECT TO :dbs
      ENDEXEC.

Here i get the sy-subrc value as 4. not sure what am i doing wrong here.

Appriciate any help.