title: Passing an optional parameter to a webservice in vb.net
body: <p>Is there a way to pass an optional parameter to a webservice, instead of having to overload the method?  </p>
  
  <p>If the webservice user is accessing the webservice directly, I want to do ActionA, if the user is accessing the webservice through my web interface, I want to do ActionA + ActionB.</p>