function ratingRequest(url) {
  var arg = url;
  url = "rating.php?q=" + url;
  var http_request = false;

  if (window.XMLHttpRequest) {
    http_request = new XMLHttpRequest();
    if (http_request.overrideMimeType) {
      http_request.overrideMimeType('text/xml');
    }
  }
  else if (window.ActiveXObject) { // IE
    try {
      http_request = new ActiveXObject("Msxml2.XMLHTTP");
    } 
    catch (e) {
      try {
        http_request = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (e) {}
    }
  }

  if (!http_request) {
    alert('Giving up :( Cannot create an XMLHTTP instance');
    return false;
  }

  http_request.onreadystatechange = function() { alertContents(http_request); };
  http_request.open('GET', url, true);
  http_request.send(null);
}

function alertContents(http_request) {
  if (http_request.readyState == 4) {
    if (http_request.status == 200) {
      document.getElementById("rating_panel").innerHTML=http_request.responseText;
    }
    else {
      alert('There was a problem with the request.');
    }
  }
}