function slideSwitch() {
    var $active = $('ul.tweets .active');
    if ( $active.length == 0 ) $active = $('ul.tweets li:last');
    var $next = $active.next().length ? $active.next() : $('ul.tweets li:first');

    $active.addClass('last-active');

    $active.fadeOut(400, function() {
      $active.removeClass('active last-active');
      $next.fadeIn(400, function() {
        $next.addClass('active')
      });
    });
        
}

$(function() {
    setInterval( "slideSwitch()", 6000 );
});