$self->option('field');
	returns value of field

 $self->option(%hash);
       sets values of fields in hash:  field=>value,field=>value. . .  
       returns:  reference to a hash of old values;
                 if the field is not a valid option
                 the field's value is set to undef;
                   
                 Because an old value may have been undefined and returns undef
                 you must use either validOption() or invalidOption()
                 to determine whether the field is in fact invalid 
                   

$opt->validOption(<option>)
$opt->invalidOption(<option>)

These test for validity of options which have been set with the option setting functions, either option() or the set_<option>() family. An invalid result occurs when attempting to set an option which does not exist.