if (document.images) {
    homebuttonup       = new Image();
    homebuttonup.src   = "images/button_home.gif" ;
    homebuttondown     = new Image() ;
    homebuttondown.src = "images/button_home_down.gif" ;

    aboutbuttonup       = new Image();
    aboutbuttonup.src   = "images/button_about.gif" ;
    aboutbuttondown     = new Image() ;
    aboutbuttondown.src = "images/button_about_down.gif" ;

	gallerybuttonup       = new Image();
    gallerybuttonup.src   = "images/button_gallery.gif" ;
    gallerybuttondown     = new Image() ;
    gallerybuttondown.src = "images/button_gallery_down.gif" ;

	hintsbuttonup       = new Image();
    hintsbuttonup.src   = "images/button_vase.gif" ;
    hintsbuttondown     = new Image() ;
    hintsbuttondown.src = "images/button_vase_down.gif" ;

	linksbuttonup       = new Image();
    linksbuttonup.src   = "images/button_contact.gif" ;
    linksbuttondown     = new Image() ;
    linksbuttondown.src = "images/button_contact_down.gif" ;
	
	blogbuttonup       = new Image();
    blogbuttonup.src   = "images/blog-button.gif" ;
    blogbuttondown     = new Image() ;
    blogbuttondown.src = "images/blog-down.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" );
    }
}