[]=

# File lib/rexml/element.rb, line 1089
    def []=( name, value )
      if value.nil?             # Delete the named attribute
        attr = get_attribute(name)
        delete attr
        return
      end
      element_document = @element.document
      unless value.kind_of? Attribute
        if @element.document and @element.document.doctype
          value = Text::normalize( value, @element.document.doctype )
        else
          value = Text::normalize( value, nil )
        end
        value = Attribute.new(name, value)
      end
      value.element = @element
      old_attr = fetch(value.name, nil)
      if old_attr.nil?
        store(value.name, value)
      elsif old_attr.kind_of? Hash
        old_attr[value.prefix] = value
      elsif old_attr.prefix != value.prefix
        # Check for conflicting namespaces
        raise ParseException.new( 
          "Namespace conflict in adding attribute \"#{value.name}\": "+
          "Prefix \"#{old_attr.prefix}\" = "+
          "\"#{@element.namespace(old_attr.prefix)}\" and prefix "+
          "\"#{value.prefix}\" = \"#{@element.namespace(value.prefix)}\"") if 
          value.prefix != "xmlns" and old_attr.prefix != "xmlns" and
          @element.namespace( old_attr.prefix ) == 
            @element.namespace( value.prefix )
          store value.name, { old_attr.prefix   => old_attr,
            value.prefix                => value }
      else
        store value.name, value
      end
      return @element
    end