if (document.images) {
   
     button1 = new Image
     button2 = new Image
	 
     button3 = new Image
     button4 = new Image
	 
     button5 = new Image
     button6 = new Image
	 
     button7 = new Image
     button8 = new Image
	 
     button9 = new Image
     button10 = new Image
	 
	 
	 	 
     button1.src = 'images/about.jpg'
     button2.src = 'images/about-hvr.jpg'
	 
	 button3.src = 'images/heating.jpg'
     button4.src = 'images/heating-hvr.jpg'
	 
     button5.src = 'images/cooling.jpg'
     button6.src = 'images/cooling-hvr.jpg'
	 
     button7.src = 'images/service.jpg'
     button8.src = 'images/service-hvr.jpg'
	 
     button9.src = 'images/contact.jpg'
     button10.src = 'images/contact-hvr.jpg'
 }