if (document.images) {
    rbuttonup       = new Image();
    rbuttonup.src   = "images/book.gif" ;
    rbuttondown     = new Image() ;
    rbuttondown.src = "images/book_animated.gif" ;
}
if (document.images) {
    hbuttonup       = new Image();
    hbuttonup.src   = "images/home.gif" ;
    hbuttondown     = new Image() ;
    hbuttondown.src = "images/home_animated.gif" ;
}
if (document.images) {
    jbuttonup       = new Image();
    jbuttonup.src   = "images/journey.jpg" ;
    jbuttondown     = new Image() ;
    jbuttondown.src = "images/journey_animated.gif" ;
}
if (document.images) {
    ebuttonup       = new Image();
    ebuttonup.src   = "images/blog.gif" ;
    ebuttondown     = new Image() ;
    ebuttondown.src = "images/blog_animated.gif" ;
}
if (document.images) {
    bbuttonup       = new Image();
    bbuttonup.src   = "images/bio.gif" ;
    bbuttondown     = new Image() ;
    bbuttondown.src = "images/bio_animated.gif" ;
}
if (document.images) {
    cbuttonup       = new Image();
    cbuttonup.src   = "images/contacts.gif" ;
    cbuttondown     = new Image() ;
    cbuttondown.src = "images/contacts_animated.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" );
    }
}