>I have installed oracle 9i and forms6i on the same machine,
WHY? Both are obsoleted.
What is Operating System name & version?
I suspect you have multiple $ORACLE_HOME folders & more than 1 tnsnames.ora files and are using an invalid copy.
12541, 00000, "TNS:no listener"
// *Cause: The connection request could not be completed because the listener
// is not running.
// *Action: Ensure that the supplied destination address matches one of
// the addresses used by the listener - compare the TNSNAMES.ORA entry with
// the appropriate LISTENER.ORA file (or TNSNAV.ORA if the connection is to
// go by way of an Interchange). Start the listener on the remote machine.
12538, 00000, "TNS:no such protocol adapter"
// *Cause: The protocol adapter requested (by way of the "(PROTOCOL=..)"
// keyword-value pair in a TNS address) is unknown. If the supplied address
// is typographically correct then the protocol adapter is not installed.
// *Action: Install the protocol adapter or correct typographically error,
// as appropriate. Note: if the supplied address was derived from
// resolving the service name, check the address in the appropriate file
// (TNSNAMES.ORA, LISTENER.ORA or SQLNET.ORA).
You can lead some folks to knowledge, but you can not make them think.
The average person thinks he's above average!
For most folks, they don't know, what they don't know.
Good judgement comes from experience. Experience comes from bad judgement.