case 1:window.location="news.htm" ;break;
case 2:window.location="catalogs.htm" ;break;
case 3:window.location="gettingstarted.htm" ;break;
case 4:window.location="newpage.htm" ;break;
                                to 
case 1:window.location="your_page_link1.htm" ;break;
case 2:window.location="your_page_link2.htm" ;break;
case 3:window.location="your_page_link3.htm" ;break;
case 4:window.location="your_page_link4.htm" ;break;