function aTraiter(obj, prefixe)
{
  return obj.id != null && obj.id.indexOf(prefixe) == 0;
}

function traiterCollection(collection, filtre, traitement)
{
  var n = collection.length;
  for (var i = 0; i < n; i++)
    if (aTraiter(collection[i], filtre) || filtre == "")
      traitement(collection[i]);      
}

function preload_is()
{
	var imgs = document.images;
	var n = imgs.length;
	for (var i = 0; i < n; i++)
	{
		var img = imgs[i];
		if (img.id.substr(0,3) == "is_")
		{
			img.Out = new Image();
			img.Out.src = img.src;
			
			img.Remp = new Image();
			img.Remp.src = img.title;
			img.title = img.alt;
			img.onmouseover = MouseOver;
			img.onmouseout = MouseOut;                       
		}
	}
}

function MouseOut()
{
	this.src = this.Out.src;
}

function MouseOver()
{
 this.src = this.Remp.src;
}