var computerURL = "imgs/computer1.jpg";

if (document.images) {
     var computer1 = new Image();
     computer1.src = "imgs/computer1.jpg";

     var computer2 = new Image();
     computer2.src = "imgs/computer2.jpg";
	 
	 var computer3 = new Image();
	 computer3.src = "imgs/computer3.jpg";
	 
	 var computer4 = new Image();
	 computer4.src = "imgs/computer4.jpg";
	 
	 var computer5 = new Image();
	 computer5.src = "imgs/computer5.jpg";
	 
	 var computer6 = new Image();
	 computer6.src = "imgs/computer6.jpg";
	 
	 var computer7 = new Image();
	 computer7.src = "imgs/computer7.jpg";
	 
	 var computer8 = new Image();
	 computer8.src = "imgs/computer8.jpg";
	 
}

function changeComputer() {
     if (document.images) {
        if (computerURL == "imgs/computer1.jpg") computerURL = "imgs/computer2.jpg";
		else if (computerURL == "imgs/computer2.jpg") computerURL = "imgs/computer3.jpg";
		else if (computerURL == "imgs/computer3.jpg") computerURL = "imgs/computer4.jpg";
		else if (computerURL == "imgs/computer4.jpg") computerURL = "imgs/computer5.jpg";
		else if (computerURL == "imgs/computer5.jpg") computerURL = "imgs/computer6.jpg";
		else if (computerURL == "imgs/computer6.jpg") computerURL = "imgs/computer7.jpg";
		else if (computerURL == "imgs/computer7.jpg") computerURL = "imgs/computer8.jpg";

		
		
         document.myComputer.src = computerURL;
	}
}