button1 = new Image();
button1.src = "./qtvr/esterno01.jpg";
button1on = new Image();
button1on.src = "./qtvr/esterno01on.jpg";

button2 = new Image();
button2.src = "./qtvr/cella25.jpg";
button2on = new Image();
button2on.src = "./qtvr/cella25on.jpg";

button3 = new Image();
button3.src = "./qtvr/IGranClaustro.jpg";
button3on = new Image();
button3on.src = "./qtvr/IGranClaustroon.jpg";

button4 = new Image();
button4.src = "./qtvr/tempio.jpg";
button4on = new Image();
button4on.src = "./qtvr/tempioon.jpg";

button5 = new Image();
button5.src = "./qtvr/claustroFerrarini.jpg";
button5on = new Image();
button5on.src = "./qtvr/claustroFerrarinion.jpg";

function imageChange(imageID,imageName) {
  document.images[imageID].src = eval(imageName + ".src");
}