My collaborative stars - not prettified:

[Gretchen Hall]

var table = document.getElementById('star_table');

var stars = table.getElementsByTagName('img');

var updateStars = function () {

      if (this.readyState == 4 && this.status == 200) {

        for (var num in this.responseText) {

          setStar(num, this.responseText[num] == "1");

        }          

    }

}

var setStar = function(starnum, state) {

   if (state) {

     stars[starnum].src = "star_on.gif";

   } else {

     stars[starnum].src = "star_off.gif";

   }

}

var clickStar = function(evt) {

  var target = stars[evt.target.id];

  if (target == null) {

    return;

  }

  var targetnum = target.id.split("_")[1];

  

  var state = target.src.endsWith("star_on.gif");

  var req = new XMLHttpRequest();

  var params = `n=${targetnum}&s=${state?"0":"1"}`;

  req.open('POST', '/collab.py');

 //Send the proper header information along with the request

  req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

  req.onreadystatechange = updateStars;

  req.send(params)

}

var requestUpdate = function() {

    var req = new XMLHttpRequest();

  req.open('GET', '/collab.py');

  req.onreadystatechange = updateStars;

  req.send()

}

table.addEventListener("click", clickStar, false)

window.setInterval(requestUpdate, 1000);