The UserName property specifies the name used to
authenticate the user. If the property is not explicitly set, then an
application may provide the user name to the Connect method.
Once the connection has been established, this property will be
updated with the appropriate value.
The UserName and Password properties are typically
required for HTTP uploads and FTP connections. They are typically not
required for HTTP downloads. If the UserName and Password
properties are undefined for an FTP connection attempt, then anonymous
FTP will be used.