# File lib/ldap/schema.rb, line 34
    def attr(oc,at)
      self['objectClasses'].each{|s|
        if( s =~ /NAME\s+'#{oc}'/ )
          case s
          when /#{at}\s+\(([\w\d_\-\s\$]+)\)/i then return $1.split("$").collect{|attr| attr.strip}
          when /#{at}\s+([\w\d_\-]+)/i then return $1.split("$").collect{|attr| attr.strip}
          end
        end
      }
      return nil
    end