// handel the navigation rollovers
if (document.images) {
// this is list of buttons
// maps button
    mapsbuttonup       = new Image();
    mapsbuttonup.src   = "assets/sidebar_maps.gif" ;
    mapsbuttondown     = new Image() ;
    mapsbuttondown.src = "assets/sidebar_maps_over.gif" ;
// prints button
	printsbuttonup       = new Image();
    printsbuttonup.src   = "assets/sidebar_prints.gif" ;
    printsbuttondown     = new Image() ;
    printsbuttondown.src = "assets/sidebar_prints_over.gif" ;
// books button
	booksbuttonup       = new Image();
    booksbuttonup.src   = "assets/sidebar_books.gif" ;
    booksbuttondown     = new Image() ;
    booksbuttondown.src = "assets/sidebar_books_over.gif" ;	
// portraits button
	portraitsbuttonup       = new Image();
    portraitsbuttonup.src   = "assets/sidebar_portraits.gif" ;
    portraitsbuttondown     = new Image() ;
    portraitsbuttondown.src = "assets/sidebar_portraits_over.gif" ;	
// location button
	locationbuttonup       = new Image();
    locationbuttonup.src   = "assets/sidebar_location.gif" ;
    locationbuttondown     = new Image() ;
    locationbuttondown.src = "assets/sidebar_location_over.gif" ;	
// schools button
	schoolsbuttonup       = new Image();
    schoolsbuttonup.src   = "assets/sidebar_schools.gif" ;
    schoolsbuttondown     = new Image() ;
    schoolsbuttondown.src = "assets/sidebar_schools_over.gif" ;	
// whatsNew button
	newbuttonup       = new Image();
    newbuttonup.src   = "assets/sidebar_new.gif" ;
    newbuttondown     = new Image() ;
    newbuttondown.src = "assets/sidebar_new_over.gif" ;	
// contact button
	contactbuttonup       = new Image();
    contactbuttonup.src   = "assets/sidebar_contact.gif" ;
    contactbuttondown     = new Image() ;
    contactbuttondown.src = "assets/sidebar_contact_over.gif" ;		
}
function buttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }
}
function buttonup ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "up.src" );
    }
}