编写一个简单的 jQuery 插件（模板）

//You need an anonymous function to wrap around your function to avoid conflict(function($){    //Attach this new method to jQuery    $.fn.extend({        //This is where you write your plugin's name        pluginname: function() {            //options            var defaults = {                option1: "default_value"            }            var options = $.extend(defaults, options);            //a public method            this.methodName: function () {                //call this method via $.pluginname().methodName();            }            //Iterate over the current set of matched elements            return this.each(function() {                var o = options;                //code to be inserted here            });        }    });//pass jQuery to the function,//So that we will able to use any valid Javascript variable name//to replace "$" SIGN. But, we'll stick to $ (I like dollar sign: ) )      })(jQuery);