var kitsURL = "imgs/kits1.jpg";

if (document.images) {
     var kits1 = new Image();
     kits1.src = "imgs/kits1.jpg";

     var kits2 = new Image();
     kits2.src = "imgs/kits2.jpg";
	 
}

function changeKits() {
     if (document.images) {
        if (kitsURL == "imgs/kits1.jpg") kitsURL = "imgs/kits2.jpg";

		
         document.myKits.src = kitsURL;
	}
}