function first_pic() {
    load_pic(pic_index);
    return;
}


function next_pic() {
    pic_index = pic_index + 1;
    if (pic_index >= pic_array.length) {
        pic_index = 0;
    }
    load_pic(pic_index);
    return;
}

function prev_pic() {
    if (pic_index == 0) {
        pic_index = pic_array.length - 1;
    }
    else {
        pic_index = pic_index - 1;
    }
    load_pic(pic_index);
    return;
}

function load_pic(index) {
    if (index >= pic_array.length) {
        index = 0;
    }
    if (document.images['sideimg']) {
        document.images['sideimg'].src = "/images/"+pic_location+"/"+pic_array[index];
    }
}