$(document).ready(function() {
    initProductInfoImages();
});

function initProductInfoImages() {
    $('.product-images .other-images a').click(function() {
        var $clickedImage = $(this).children('img');
        var $mainImage = $(this).parent().parent().children('.main-image').children('img');
        var newSrc = $clickedImage.attr('src');
        var oldSrc = $mainImage.attr('src');
        $mainImage.attr('src', newSrc); 
        $clickedImage.attr('src', oldSrc);
    });
}