function startLooping()
{
  var cnt=countImages();
  var idx=Math.floor(Math.random() * cnt);
  $("#rightimg_"+idx).css("display", "block");
  startWaiting(idx);
}

function countImages()
{
  var idx=0;
  while (true) {
    var elem=document.getElementById("rightimg_"+idx);
    if (!elem) {
      break;
    }
    idx += 1;
  }
  return idx;
}

function startWaiting(idx)
{
  window.setTimeout("startFadeout("+idx+")", 5500);
}

function startFadeout(idx)
{
  var nextIdx=idx+1;
  var elem=document.getElementById("rightimg_"+nextIdx);
  if (!elem) {
    nextIdx=0;
  }

  $("#rightimg_"+idx).fadeOut(700, function() { startFadein(nextIdx); });
}

function startFadein(idx)
{
  $("#rightimg_"+idx).fadeIn(700, function() { startWaiting(idx); });
}