function image() { }; image = new image(); number = 0; image[number++] = "caldaie a biomasse Tatano" image[number++] = "stufe a legna Castelmonte" image[number++] = "stufe termocucine caldaie Thermorossi" image[number++] = "Newcomen energia elettrica da sorgenti termiche non utilizzate" image[number++] = "termostufe stufe caldaie Ravelli" a1 = Math.floor(Math.random() * number);