var counter = 0;
var max = 0;
var t;
var delay_time = 5000; // 5 sec delay before each slide.

window.onload = function() {
  max = $('#panel_navigation a').length - 1;
  loop_panel();
}

var loop_panel = function() {
  t = setTimeout("loop_panel(); next_panel();", delay_time);
}

var next_panel = function() {
  if (counter >= max)
    counter = 0;
  else
    counter++;  
  show_panel(counter, false);
}

var show_panel = function(num, clear) {
  if (clear) clearTimeout(t);
  for (i=0; i<=max; i++)
    $('#panel_'+(i))[0].style.display='none';
  for (i=0; i<=max; i++)
    $('#panel_navigation a.active').eq(0).removeClass('active');
  $('#panel_'+(num))[0].style.display = 'block';
  $('#panel_navigation a').eq(num).addClass('active');
  $('#panel_navigation a')[num].blur();
}