if (document.images) {
      
      back_gallery = new Image();
      back_gallery.src = "images/btn_back_gallery_off.gif";
      back_galleryover = new Image();
      back_galleryover.src = "images/btn_back_gallery_on.gif";
      
      prev_photo = new Image();
      prev_photo.src = "images/btn_prev_photo_off.gif";
      prev_photoover = new Image();
      prev_photoover.src = "images/btn_prev_photo_on.gif";
      
      next_photo = new Image();
      next_photo.src = "images/btn_next_photo_off.gif";
      next_photoover = new Image();
      next_photoover.src = "images/btn_next_photo_on.gif";
      
      back_list = new Image();
      back_list.src = "images/btn_back_list_off.gif";
      back_listover = new Image();
      back_listover.src = "images/btn_back_list_on.gif";
      
      prev_player = new Image();
      prev_player.src = "images/btn_prev_player_off.gif";
      prev_playerover = new Image();
      prev_playerover.src = "images/btn_prev_player_on.gif";
      
      next_player = new Image();
      next_player.src = "images/btn_next_player_off.gif";
      next_playerover = new Image();
      next_playerover.src = "images/btn_next_player_on.gif";
      
      
      back_documents = new Image();
      back_documents.src = "images/btn_back_documents_off.gif";
      back_documentsover = new Image();
      back_documentsover.src = "images/btn_back_documents_on.gif";
      
      prev_page = new Image();
      prev_page.src = "images/btn_prev_page_off.gif";
      prev_pageover = new Image();
      prev_pageover.src = "images/btn_prev_page_on.gif";
      
      next_page = new Image();
      next_page.src = "images/btn_next_page_off.gif";
      next_pageover = new Image();
      next_pageover.src = "images/btn_next_page_on.gif";
      
      
     
      
}          

function over(name){
        if (document.images){
                document[name].src = eval(name + "over.src");
        }
}
function off(name){
        if (document.images){
                document[name].src = eval(name + ".src");
        }
}

function popup(pagename,windowname,width,height,scroll) {
	var popup = window.open(pagename,windowname,"toolbar=no,directories=no,location=no,status=no,menubar=no,scrollbars="+scroll+",resizable=no,width="+width+",height="+height+",left=0,top=0");

    popup.focus();

}