function alleatoire() {
	var nombre_images = 10;
	var nombre_alleatoire = Math.random();
	var numero = Math.round( ( nombre_images - 1 ) * nombre_alleatoire ) + 1;

	images = new Array;
	images[1] = "1.gif";
	images[2] = "2.gif";
	images[3] = "3.gif";
	images[4] = "4.gif";
	images[5] = "5.gif";
	images[6] = "6.gif";
	images[7] = "7.gif";
	images[8] = "8.gif";
	images[9] = "9.gif";
	images[10] = "10.gif";

	var image = images[numero];
	document.image_changeante.src = "../media/javascript/" + image;
	}