AuthenticateUser

Visual Basic (declaration)
Public Function AuthenticateUser( _ ByVal UID as String, _ ByVal PWD as String) as XmlNode

C# (declaration)
public XmlNode AuthenticateUser( string UID, string PWD)

UID
    string The username of the user to be authenticated
PWD
    string The password of the user to be authenticated

returns xml fragment.
<response success="true" ticket="sid-xxxxxxx" error="">
if success attribute is "true", the user has been authenticated successfully.
if success attribute is "false", the error attribute indicates the encountered error.
You must use the authentication token returned in the ticket attribute in all subsequent calls.

CreateTicketforUser | isValidTicket | LogOut