//nav
if(document.images){
  var main = new Image(); main.src = "images/menu/menu_main.png";
  var img1 = new Image(); img1.src = "images/menu/menu_online_shop.png";
  var img2 = new Image(); img2.src = "images//menu/menu_our_store.png";
  var img3 = new Image(); img3.src = "images/menu/menu_about_us.png";
  var img4 = new Image(); img4.src = "images/menu/menu_contact.png";
  var img5 = new Image(); img5.src = "images/menu/menu_letter_writing_club.png";
  var img6 = new Image(); img6.src = "images/menu/menu_lowercase_gallery.png";
  var img7 = new Image(); img7.src = "images/menu/menu_press.png";
}
function change(imageName){
  if(document.images){ document['main'].src = eval(imageName + ".src"); }
}
function changeBack(){
  if(document.images){ document['main'].src = main.src; }
}