title: Avoid to create session in WCF
body: <p>Is there a way to cancel the creation of the session if the method with the IsInitiating causes a validation error? </p>
  
  <p>I am requiring the user and password in the first method and I do not want to create the session if the credentials are not valid. In fact, I want to return an object indicating if the credentials validation were successful.</p>
  
  <p>Thank you in advance.</p>