var b     = new Array();
var bo    = new Array();
for(i = 0; i < 4; i++) {
  b[i] = new Image();
  bo[i] = new Image();
}
var snow1 = new Image();
var snow2 = new Image();
var logo1 = new Image();
var logo2 = new Image();
snow1.src = "/_img/snow.gif";
snow2.src = "/_img/snow-over.gif";
logo1.src = "/_img/logo.jpg";
logo2.src = "/_img/logo-over.jpg";
b[0].src  = "/_img/b-tipp.gif";
b[1].src  = "/_img/b-hoteldirekt.gif";
b[2].src  = "/_img/b-veranstaltungen.gif";
b[3].src  = "/_img/b-zimmerfrei.gif";
bo[0].src = "/_img/b-tipp-over.gif";
bo[1].src = "/_img/b-hoteldirekt-over.gif";
bo[2].src = "/_img/b-veranstaltungen-over.gif";
bo[3].src = "/_img/b-zimmerfrei-over.gif";
function on(img) {
  document.images[img].src = snow2.src;
}
function off(img) {
  document.images[img].src = snow1.src;
}
function on2() {
  if( document.images["logo"] )
    document.images["logo"].src = logo2.src;
  else if (document.layers["logo"].document.images["logo"])
    document.layers["logo"].document.images["logo"].src = logo2.src;
}
function off2() {
  if( document.images["logo"] )
    document.images["logo"].src = logo1.src;
  else if (document.layers["logo"].document.images["logo"])
    document.layers["logo"].document.images["logo"].src = logo1.src;
}
function on3(img) {
  document.images["b" + img].src = bo[img].src;
}
function off3(img) {
  document.images["b" + img].src = b[img].src;
}