Jquery pluign development example

(function($){

    $.fn.ChangeStyle = function(options,msg){

var opts = $.extend({},$.fn.ChangeStyle.defaults, options); 

this.css("background",opts.background);  
this.css("color",opts.color); 

//private method
            Note(msg);

//public method
            $.fn.ChangeStyle.customAction();

        };
function Note(msg)
    {

if(undefined != msg)
        {
            alert(msg);
        }
    }

    $.fn.ChangeStyle.defaults = { background:"#999",color:"red"};

    $.fn.ChangeStyle.customAction = function(){};

})(jQuery);


//Invoke the pluign example
$(function()
{

 //set properties
 //$("form").ChangeStyle.defaults.background = "#f1f1f1";
 //$("form").ChangeStyle.defaults.color = "blue";

 $("form").ChangeStyle.customAction = function(){ alert("this is custom action")};
 $("form").ChangeStyle({ background:"#999",color:"red"},"hi");


});