$key
->QueryKey($class
, $subs
, $vals
)
Retrieves information about the current key and returns it to
the named scalar variables. The key class is saved in the
class variable (it will be the null string ""
on Win95
since it doesn't use key classes). The number of subkeys is saved in the
$sub variable, and the number of values in the current key is
saved in $vals.