ORA-27375: valid agent name must be specified for secure queues
Cause : The queue specified for the event based job or schedule was a secure queue and either no agent name was specified or an invalid agent name was specified.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
If no agent name was specified, retry the call with a valid agent name. If the agent name was valid, check if the agent is currently subscribed to the queue and, in the case of jobs, check is the agent has been authorized to act as the job owner.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.