Sum Checked Checkbox Value jQuery

jQuery('.weekly_service input:checkbox').change(function ()
{
      var total = 0;
      jQuery('input:checkbox:checked').each(function(){ // iterate through each checked element.
        total += isNaN(parseInt(jQuery(this).val())) ? 0 : parseInt(jQuery(this).val());
      });     
      jQuery(".all_total input").val(total);
 });