def csv
    @charity = Charity.find(params[:id])
    donations_count = @charity.get_all_donations_month_wise(params[:window].to_i)
    month_names = get_previous_months_name_array(params[:window].to_i)
    #csv_array= Array.new
    #logger.info  month_names.inspect
    #logger.info  donations_count.inspect
    #donations_count.each_with_index do |i,j|
    #  csv_array[j] = {month_names[j] => donations_count[j]}
    #end
    #logger.info  csv_array.inspect
    csv_string = FasterCSV.generate do |csv|
      csv << ["Month Name","Donation count"]
      donations_count.each_with_index do |i,j|

        csv << [month_names[j] , donations_count[j]     ]

      end
    end
    send_data csv_string,
              :type => "text/csv; charset=iso-8859-1; header=present",
              :disposition => "attachment; filename=charity.csv"
  end