var productImages = [];

// Preloaded image. ID = 55
productImages[55] = new Image();
productImages[55].src="/image/product/medium/crunchyapples_a.jpg";
productImages[55].alt = "Crunchy apples zip pouch";

         

// Preloaded image. ID = 56
productImages[56] = new Image();
productImages[56].src="/image/product/medium/crunchyapples_b.jpg";
productImages[56].alt = "Crunchy apples zip pouch";

         
function swapImage(image) {
   document.prodImageMain.src = productImages[image].src; 
}