// Make visible all the png images on the page.
// (c) The Univerisity of Auckland.
// Author: Craig Housley. Updated 18-March-2005.

function showPNG() 
   {
   for(var i=0; i<document.images.length; i++)
      {
	  var img = document.images[i]
	  var imgName = img.src.toUpperCase()
	  if (imgName.substring(imgName.length-3, imgName.length) == "PNG")
	     {
		 	img.style.visibility="visible" 
	     }
      }
   }