$(document).ready(function(){

    // Hide all large images except the first one
    $('#imageContainer img').hide().filter(':first').show();

    // Select all thumb links
    $('#thumbContainer a').hover(function(event) {

            // Hide all large images except for the one with the same hash as our thumb link
            $('#imageContainer img').hide().filter(this.hash).show();
        },
        function () {} // Because the hover method has a mouseout state we need to define too
    );
});