# File lib/arrayfields.rb, line 73
    def []=(idx, *args) 
      if @fieldset and (String === idx or Symbol === idx) 
        pos = @fieldset.pos idx
        unless pos
          @fieldset.fields << idx
          @fieldset.fieldpos[idx] = pos = size
        end
        super(pos, *args)
      else
        super
      end
    end