Gets a single license values for the current license.

Parameters: Two <string> values, which must be specified in the following order:

product – the Product ID code for the product you want to query.
varname – the name of the value to retrieve.

Return values: A <struct> of name-value pairs, containing the following values:

value type description
error <int> An error code. See below for a list of error codes.
message <string> A text description of the error code.
(value name)   The value requested; may be null if the value was not set.