ORA-29542: class string already defined by source string
Cause : An attempt was made to create a Java source object that would define a class that is already defined by a different Java source object.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Either drop the old source or modify the new source.
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.