pic017 = new Image();
pic017.src = "gallery/017.jpg";

pic018 = new Image();
pic018.src = "gallery/018.jpg";

pic019 = new Image();
pic019.src = "gallery/019.jpg";

pic020 = new Image();
pic020.src = "gallery/020.jpg";

pic021 = new Image();
pic021.src = "gallery/021.jpg";

pic022 = new Image();
pic022.src = "gallery/022.jpg";

pic023 = new Image();
pic023.src = "gallery/023.jpg";

pic024 = new Image();
pic024.src = "gallery/024.jpg";

function showpic(item) {
   document.getElementById('bigpic').src=eval(item).src;
}