Pradip,
If it is a Java Client, make sure you Java client artifacts include a Java implementation of WS-Security. WS-Security allows to represent "username/password" tokens in
SOAP messages.
For a quick hello world example, I would suggest you to read the Java Web Services Tutorial for JWSDP 1.5 (Posted in java.sun.com). If you want to try out a
Pattern check Chapter 11 (Web Services Security Patterns) and Chapter 7 (WS Security standards) both chapters discusses on how to implement Message-level security (including code examples) and strategies.
/Ramesh