direction : 'down'
base.start_interval = function(){
//Clear out any existing interval
clearInterval(base.ticker);
base.ticker = setInterval(function() {
base.$el.find('li:last').detach().prependTo(base.$el).css('marginTop', '-' + base.options.row_height);
base.$el.find('li:first').animate({
marginTop: '0px',
}, base.options.speed, function () {
base.reset_interval();
});
}, base.options.interval);
}