def index
  if params[:start_date] && params[:start_date].is_a?(Hash)
    #the user provided a date
    @start_date = Date.new(params[:start_date][:year].to_i, params[:start_date][:month].to_i, params[:start_date][:day])
  elsif params[:start_date]
    #they provided a date in string format (probably for the json)
    @start_date = Date.parse(params[:start_date])
  else
    #lets use a default date
    @start_date = 3.months.ago.to_date
  end
  #do the same thing for end date
  if params[:end_date] && params[:end_date].is_a?(Hash)
    #the user provided a date
    @end_date = Date.new(params[:end_date][:year].to_i, params[:end_date][:month].to_i, params[:end_date][:day])
  elsif params[:end_date]
    #they provided a date in string format (probably for the json)
    @end_date = Date.parse(params[:end_date])
  else
    #lets use a default date
    @end_date = 3.months.ago.to_date
  end

  respond_to do |wants|
    wants.html {
      @graph = open_flash_chart_object( 600, 300, stats_url(:format => :json, :start_date => @start_date, :end_date => @end_date))
    }
    wants.json {
      @stats = Stat.between_dates(@start_date, @end_date) #or whatever your find method is called.
      #build a chart
      chart = OpenFlashChart.new( "Data between #{@start_date} and #{@end_date}" ) do |c|
        #TODO make the bar chart have axis values as well for the dates....
        c << BarGlass.new( :values => @stats.map{|s| s.value} )
      end
      render :text => chart, :layout => false
    }
  end
end