Use EndUserAdapter to get or set the interface of the end user adapter. An end user adapter maintains information about the current end user, and supports the actions for logging users in and out. End user adapters implement the fields and actions of the EndUser variable in server-side scripts. 

Typically, EndUserAdapter is the interface of a TEndUserAdapter or TEndUserSessionAdapter object. If the WebSnap application does not include a component that implements the IWebEndUser interface, the value of this property is nil (Delphi) or NULL (C++). When EndUserAdapter is nil (Delphi) or NULL (C++), the WebSnap application can't use the EndUser variable in server-side scripts or take advantage of the login support that end user adapters provide. 

TEndUserAdapter 

TEndUserSessionAdapter