img01=new Image();
      img01.src="images/home_button_car.jpg";
      img02=new Image();
      img02.src="images/home_button_car_h.jpg";
	  img03=new Image();
      img03.src="images/home_button_truck.jpg";
      img04=new Image();
      img04.src="images/home_button_truck_h.jpg";
	  		
	 function Over(id,number){
 			document.images[id].src=eval('img'+number+'.src');
		}