function displayBlock(id) {
		var size = document.getElementsByName('ref').length;
		for (var i=1;i<=size;i++) {
			toDisplay = i==id ? 'block' : 'none';
			document.getElementById('ref['+i+']').style.display=toDisplay;
		}
	}

	function rollover() {
	  if (!document.getElementById) return
	  var imgOrSrc;
	  var imgPreload = new Array();
	  var images = document.getElementsByTagName('img');
	  for (var i = 0; i < images.length; i++) {
		if (images[i].getAttribute('rsrc')) {
		  imgPreload[i] = new Image();
		  imgPreload[i].src = images[i].getAttribute('rsrc');
		  images[i].onmouseover = function() {
			imgOrSrc = this.getAttribute('src');
			this.setAttribute('src',this.getAttribute('rsrc'))
		  }
		  images[i].onmouseout = function() {
			this.setAttribute('src',imgOrSrc)
		  }
		}
	  }
	}