var current_image = 0;
	var image = new Array();
	
	function changeImage(next_image) {
		if (current_image != next_image) {
			opacity("image" + current_image, 100, 0, 500);
			opacity("image" + next_image, 0, 100, 500);
			current_image = next_image;
		}
	}

	function opacity(id, opacStart, opacEnd, millisec) {
		//speed for each frame
		var speed = Math.round(millisec / 100);
		var timer = 0;

		//détermine le sens de transition : fadein ou fadeout
		if(opacStart > opacEnd) {
			for(i = opacStart; i >= opacEnd; i--) {
				setTimeout("changeOpacity(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
		} else if(opacStart < opacEnd) {
			for(i = opacStart; i <= opacEnd; i++) {
				setTimeout("changeOpacity(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
		}
	}

	//change the opacity for different browsers
	function changeOpacity(opacity, id) {
		var object = document.getElementById(id).style;
		object.opacity = (opacity / 100);
		object.MozOpacity = (opacity / 100);
		object.KhtmlOpacity = (opacity / 100);
		object.filter = "alpha(opacity=" + opacity + ")";
	}