tinyscrollbar jquery

i tried to make scroll hight of tiny-scroll to 100%

JavaScript

$(function() {  
    $(window).resize(function(){
        var heightscroll = $(window).height();
        $('.viewport').css('height', heightscroll-48);              
        var oScrollbar = $('.scrollbar1');
        oScrollbar.tinyscrollbar();
        oScrollbar.tinyscrollbar_update();
    });
    $(window).resize();
});