if (document.images) {
homeon = new Image();
homeon.src = "images/homey.gif";

homeoff = new Image();
homeoff.src = "images/homeo.gif";

philoson = new Image();
philoson.src = "images/philosy.gif";

philosoff = new Image();
philosoff.src = "images/philoso.gif";

serviceon = new Image();
serviceon.src = "images/servicey.gif";

serviceoff = new Image();
serviceoff.src = "images/serviceo.gif";

clienton = new Image();
clienton.src = "images/clienty.gif";

clientoff = new Image();
clientoff.src = "images/cliento.gif";

contacton = new Image();
contacton.src = "images/contacty.gif";

contactoff = new Image();
contactoff.src = "images/contacto.gif";

}

function ex(id,name){
  if (document.images) document.images[id].src=eval(name+".src");
}