text: (function($){
      $.fn.snow = function(options){
      var $flake = $('<div id="snowbox" />').css({'position': 'absolute','z-index':'9999', 'top': '-50px'}).html('❄'),
      documentHeight  = $(document).height(),
      documentWidth   = $(document).width(),
      defaults = {
          minSize     : 10,
          maxSize     : 20,
          newOn       : 1000,
          flakeColor  : "#AFDAEF"  //雪花颜色
      },
  options = $.extend({}, defaults, options);
      var interval= setInterval( function(){
      var startPositionLeft = Math.random() * documentWidth - 100,
      startOpacity = 0.5 + Math.random(),
      sizeFlake = options.minSize + Math.random() * options.maxSize,
      endPositionTop = documentHeight - 200,
      endPositionLeft = startPositionLeft - 500 + Math.random() * 500,
      durationFall = documentHeight * 10 + Math.random() * 5000;
      $flake.clone().appendTo('body').css({
          left: startPositionLeft,
          opacity: startOpacity,
          'font-size': sizeFlake,
          color: options.flakeColor
      }).animate({
          top: endPositionTop,
          left: endPositionLeft,
          opacity: 0.2
      },durationFall,'linear',function(){
          $(this).remove()
      });
      }, options.newOn);
      };
  })(jQuery);
  $(function(){
      $.fn.snow({ 
          minSize: 5, 
          maxSize: 50,
          newOn: 300
      });
  });
  