function initImage( name ) {

  var image = document.getElementById( name );
  image.style.visibility = 'visible';
  fadeIn(name,2);

}

function setOpacity(obj, opacity) {

  if( opacity > 100 )
    opacity = 100;

  // IE/Win
  obj.style.filter = "alpha(opacity:"+opacity+")";
  
  // Safari<1.2, Konqueror
  obj.style.KHTMLOpacity = opacity/100;
  
  // Older Mozilla and Firefox
  obj.style.MozOpacity = opacity/100;

  // Safari 1.2, newer Firefox and Mozilla, CSS3
  obj.style.opacity = opacity/100;
}

function fadeIn(objId,opacity) {

  var obj = document.getElementById(objId);
  setOpacity(obj, opacity);

  if( opacity > 100 )
    return;

  var wait = 30;

  switch( opacity )
  {
    case 0.6 :
      opacity = 101;
      wait = 80;
      break;

    case 99.5 :
      opacity = 0.6;
      wait = 80;
      break;

    case 0.5 :
      opacity = 99.5;
      wait = 80;
      break;

    case 92 :
      opacity = 0.5;
      wait = 80;
      break;

    default :
      opacity += 10;
      wait = 30;
      break;
  }

  window.setTimeout("fadeIn('"+objId+"',"+opacity+")", wait);    
}

/* AJAX bits */

function replaceImage( name ) {

  var image = document.getElementById( name );
  image.style.visibility = 'visible';
}

/* Create a new XMLHttpRequest object to talk to the Web server */
var xmlHttp = false;
/*@cc_on @*/
/*@if (@_jscript_version >= 5)
try {
  xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
  try {
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  } catch (e2) {
    xmlHttp = false;
  }
}
@end @*/

window.setTimeout("getImage()", 20000);  // 20 seconds

if (!xmlHttp && typeof XMLHttpRequest != 'undefined') {
  xmlHttp = new XMLHttpRequest();
}

function getImage()
{
  document.getElementById( "th_info" ).innerHTML="!";
  
  var url = "http://teethgrinder.co.uk/include/thumb-ajax.php";

  // Open a connection to the server
  xmlHttp.open("GET", url, true);

  // Setup a function for the server to run when it's done
  xmlHttp.onreadystatechange = updatePage;

  // Send the request
  xmlHttp.send(null);
}

function updatePage() {
  if (xmlHttp.readyState == 4) {
    var response = xmlHttp.responseText;
    
    var thumb = ( Math.round( 4*Math.random() ) + 1);
    var r = "thumb_" + thumb;
    var s = "thumb_link_" + thumb;

    document.getElementById( "th_info" ).innerHTML="?";
   
    var r_array = response.split("|");
    
    if( r_array.length == 2 )
    {
      document.getElementById( r ).src = r_array[0];
      document.getElementById( s ).href = r_array[1];
    }
    
    window.setTimeout("getImage()", 20000);
  }
}