ORA-23430: argument "string" cannot be NULL or empty string
Cause : The caller has provided an argument whose value cannot be NULL or the empty string.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Check that the varchar2 value provided is not NULL or the empty string, and retry the call.
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.