ORA-27454: argument name and position cannot be NULL
Cause : The name or position of a program or job argument was defined as NULL.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Reissue the command providing either a valid argument name or valid argument position.
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.