Method design question...and passing object as parameter to webserice

Question

I am new to webservice...one design question
i am writing a webservice to check whether a user is valid user or not. The users are categorized as Member, Admin and Professional. For each user type I have to hit different data source to verify.
I can get this user type as parameter. What is the best approach to define the method?
Having one single method �isValidUser � and all the client web service can always call this method and provide user type or should I define method for each type like isValidMember, isValidAdmin ?
One more thing...in future the requirement may change for professional to have more required field in that case the parameter need to have more attribute. But on client side not much change if I have a single isValidUser method...all they have to do is pass additional values
isValidUser(String username, String usertype, String[] userAttributes){
if usertype == member
call member code
else if usertype = professional
call professional code
else if usertype = admin
call admin code
else
throw error
or
isValidMember(String username, String[] userAttributes){
call member code
One last question, can the parameter be passed as object in web service like USER object.

Answer 1

First of all, here is my code
CREATE OR REPLACE
TYPE USERCONTEXT AS OBJECT
user_login varchar2,
user_id integer,
CONSTRUCTOR FUNCTION USERCONTEXT (
P_LOGIN IN INTEGER
P_ID_ID IN INTEGER
) RETURN SELF AS RESULT
Either your type wont be compiled or this is not the real code..