追加addclass和removeclass

//addclass

            Base.prototype.addclass=function(classname){

                for(var i=0;i<this.elements.length;i++)

                {

                    //去重

                    if(!this.elements[i].className.match(new RegExp('(\\s|^)'+classname+'($|\\s)')))

                    {

                        this.elements[i].className+=" "+classname

                    }

 

                }

                return this;

            }

            //removeclass

            Base.prototype.removeclass=function(classname){

                for(var i=0;i<this.elements.length;i++)

                {

                    //去重

                    if(this.elements[i].className.match(new RegExp('(\\s|^)'+classname+'($|\\s)')))

                    {

                        this.elements[i].className=this.elements[i].className.replace(new RegExp('(\\s|^)'+classname+'($|\\s)'))," ")

                    }

 

                }

                return this;

            }