$('#scroll-trigger').click(function() {
      this.hide();
      var viewport = $('#container');
      $('#scroll-overlay')
        .css('left', viewport.css('left'))
        .css('top', viewport.css('top'))
        .css('width', viewport.width())
        .css('height', viewport.height())
        .css('z-index', 99)
        .css('display', '');