function changeImage(element, changeTo) {

	
	var mainImage = document.getElementById("mainImage");

	var selectedThumbnail = element.getAttribute("id");

	if (selectedThumbnail == "one") {

		mainImage.setAttribute("src", changeTo);
	
	} else if (selectedThumbnail == "two") {

		mainImage.setAttribute("src", changeTo);

	} else if (selectedThumbnail == "three") {

		mainImage.setAttribute("src", changeTo);

	}

}