if (document.images) {
        img1on = new Image();
        img1on.src = "images/btn_home_on.gif";
        img1off = new Image();
        img1off.src = "images/btn_home.gif"
        
		img2on = new Image();
        img2on.src = "images/btn_aboutus_on.gif";
        img2off = new Image();
        img2off.src = "images/btn_aboutus.gif"
		
		img3on = new Image();
        img3on.src = "images/btn_services_on.gif";
        img3off = new Image();
        img3off.src = "images/btn_services.gif"
		
		img4on = new Image();
        img4on.src = "images/btn_gallery_on.gif";
        img4off = new Image();
        img4off.src = "images/btn_gallery.gif"	
		
		img5on = new Image();
        img5on.src = "images/btn_testimonials_on.gif";
        img5off = new Image();
        img5off.src = "images/btn_testimonials.gif"	
		
		img6on = new Image();
        img6on.src = "images/btn_roofing101_on.gif";
        img6off = new Image();
        img6off.src = "images/btn_roofing101.gif"
        
        img7on = new Image();
        img7on.src = "images/btn_faq_on.gif";
        img7off = new Image();
        img7off.src = "images/btn_faq.gif"	
		
		img8on = new Image();
        img8on.src = "images/btn_contactus_on.gif";
        img8off = new Image();
        img8off.src = "images/btn_contactus.gif"
		
		
}
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;
    }
 }