/*
 * news scroller : plugin
*/
// Create a self-invoking anonymous function. That way,  
// we're free to use the jQuery dollar symbol anywhere within.  
(function($) {  
  
// We name our plugin "newscroll". When creating our function,  
// we'll allow the user to pass in a couple of parameters.  
$.fn.newsScroll = function(options) {  
  
    // For each item in the wrapped set, perform the following.  
    return this.each(function() {     
  
        var  
          // Caches this - or the ul widget(s) that was passed in.  
          //  Saves time and improves performance.  
          $this = $(this),   
  
          // If the user doesn't pass in parameters, we'll use this object.  
          defaults = {  
            speed: 400, // How quickly should the items scroll?  
            delay: 4000, // How long a rest between transitions?  
            list_item_height: $this.children('li').outerHeight() // How tall is each list item? If this parameter isn't passed in, jQuery will grab it.  
         },  
          // Create a new object that merges the defaults and the  
          // user's "options".  The latter takes precedence.  
          settings = $.extend({}, defaults, options);  
  
      // This sets an interval that will be called continuously.  
      setInterval(function() {  
            // Get the very first list item in the wrapped set.  
            $this.children('li:first')  
                    // Animate it  
                    .animate({  
                        marginTop : '-' + settings.list_item_height // Shift this first item upwards.  
                      // opacity: 'hide' // Fade the li out.
                       },   
  
                       // Over the course of however long is  
                       // passed in. (settings.speed)  
                       settings.speed,   
  
                       // When complete, run a callback function.  
                       function() {  
  
                        // Get that first list item again.  
                            $this.children('li:first')  
                                 .appendTo($this) // Move it the very bottom of the ul.  
  
                                 // Reset its margin top back to 0. Otherwise,  
                                 // it will still contain the negative value that we set earlier.  
                                 .css('marginTop', 0)  ;
                                 //.fadeIn(300); // Fade in back in.  
                      }  
                  ); // end animate  
      }, settings.delay); // end setInterval  
      });  
}  
  
})(jQuery);