jquery expand

/**
* jquery-expand-1.0.js
* author:tww
**/
(function(){

    /**
    * jQuery fadeTo expand.
    **/
    jQuery.fn._fadeTo = function(timer,opacity){
        var that = this;
        var fadeTo_default=timer;
        this._interval = setInterval(function(){
            fadeTo_default =fadeTo_default-(1-opacity)*100;
            if(fadeTo_default/timer<=opacity){
                clearInterval(_interval);
            }
            jQuery(that).css("opacity",fadeTo_default/timer);
        },100);    

        this.stop=function(){
            window.clearInterval(this._interval);
        }
        return this;
    }
})();