nav_art = new Image();      
nav_art.src = "images/nav_art_r.gif"; 

nav_about = new Image();      
nav_about.src = "images/nav_about_r.gif"; 

nav_news = new Image();      
nav_news.src = "images/nav_news_r.gif"; 

nav_houseboat = new Image();      
nav_houseboat.src = "images/nav_houseboat_r.gif"; 

nav_contact = new Image();      
nav_contact.src = "images/nav_contact_r.gif"; 

nav_home = new Image();      
nav_home.src = "images/nav_home_r.gif";