if (document.images)
   {
     pic1on= new Image(54,35);
     pic1on.src="images/bt_01_home_hov.jpg";  
     pic1off= new Image(54,35);
     pic1off.src="images/bt_01_home.jpg";
     
     pic2on= new Image(72,35);
     pic2on.src="images/bt_02_profile_hov.jpg";  
     pic2off= new Image(72,35);
     pic2off.src="images/bt_02_profile.jpg";
     
     pic3on= new Image(54,35);
     pic3on.src="images/bt_03_news_hov.jpg";  
     pic3off= new Image(54,35);
     pic3off.src="images/bt_03_news.jpg";
     
     pic4on= new Image(70,35);
     pic4on.src="images/bt_04_article_hov.jpg";  
     pic4off= new Image(70,35);
     pic4off.src="images/bt_04_article.jpg";
     
     pic5on= new Image(74,35);
     pic5on.src="images/bt_05_gallery_hov.jpg";  
     pic5off= new Image(74,35);
     pic5off.src="images/bt_05_gallery.jpg";
     
     pic6on= new Image(64,35);
     pic6on.src="images/bt_06_forum_hov.jpg";  
     pic6off= new Image(64,35);
     pic6off.src="images/bt_06_forum.jpg";
     
     pic7on= new Image(89,35);
     pic7on.src="images/bt_07_download_hov.jpg";  
     pic7off= new Image(89,35);
     pic7off.src="images/bt_07_download.jpg";
     
     pic8on= new Image(81,35);
     pic8on.src="images/bt_08_contact_hov.jpg";  
     pic8off= new Image(81,35);
     pic8off.src="images/bt_08_contact.jpg";
   }

	function lightup(imgName)
	 {
	   if (document.images)
	    {
	      imgOn=eval(imgName + "on.src");
	      document[imgName].src= imgOn;
	    }
	 }
	
	function turnoff(imgName)
	 {
	   if (document.images)
	    {
	      imgOff=eval(imgName + "off.src");
	      document[imgName].src= imgOff;
	    }
	 }