if (document.images) {
	  image1on = new Image();
	  image1on.src = "image/aboutus_roll.gif";
	
	  image2on = new Image();
	  image2on.src = "image/register_roll.gif";
	
	  image3on = new Image();
	  image3on.src = "image/portfolio_roll.gif";
	
	  image4on = new Image();
	  image4on.src = "image/links_roll.gif";
	
	  image5on = new Image();
	  image5on.src = "image/news_roll.gif";
		
	  image1off = new Image();
	  image1off.src = "image/aboutus.gif";
	
	  image2off = new Image();
	  image2off.src = "image/register.gif";
	
	  image3off = new Image();
	  image3off.src = "image/portfolio.gif";
	
	  image4off = new Image();
	  image4off.src = "image/links.gif";
	
	  image5off = new Image();
	  image5off.src = "image/news.gif";
	
	}

	function changeImages() {
		if (document.images) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
      	document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    	}
  		}
	}