$(document).ready(function() {

	var theImages = new Array(
							  	'/images/layout/random/rnd1.jpg',
								'/images/layout/random/rnd2.jpg',
								'/images/layout/random/rnd3.jpg',
								'/images/layout/random/rnd4.jpg',
								'/images/layout/random/rnd5.jpg',
								'/images/layout/random/rnd6.jpg'
							  )
	
	$('#immagine_centrale').css({'background-image' : 'url('+theImages[(Math.floor(Math.random()*theImages.length))]+')'});

});