image1 = new Image();
image1.src = "images/menu_firma_on.jpg";

image2 = new Image();
image2.src = "images/menu_oferta_on.jpg";

image3 = new Image();
image3.src = "images/menu_realizacje_on.jpg";

image4 = new Image();
image4.src = "images/menu_referencje_on.jpg";

image5 = new Image();
image5.src = "images/menu_kontakt_on.jpg";