button_home = new Image();
button_home.src = 'img/button_home_over.gif';

button_biography = new Image();
button_biography.src = 'img/button_biography_over.gif';

button_timesandplaces = new Image();
button_timesandplaces.src = 'img/button_timesandplaces_over.gif';

button_gallery = new Image();
button_gallery.src = 'img/button_gallery_over.gif';

button_contactus = new Image();
button_contactus.src = 'img/button_contactus_over.gif';