// mettre un minimum de 4 images !!!

		var coef = 0.07 ; // avancement de l'opacite
		var temps = 100 ; // temps entre chaque changement d'opacite
		var temps_pause = 3700 ; // temps d'attente entre 2 changements d'images
		var nombre_image = 17 ; // nombre d'images a faire bouger
		var prefix_image = 'image/diapo_acceuil/diapo'; // chemin + prefix du nom des images
		var suffix_image = '.jpeg' ; // suffix + '.extension' du nom des images

		// pas touche
		var indice = 2; // les 2 premiere image sont deja charger dans le HTML, on commence a la 3eme
		var isIE = navigator.userAgent.toLowerCase().indexOf('msie')!=-1 ;
		var img1 = null;
		var img2 = null ;
		var sens = 1;
		var tabImg;  // tab contenant les images
		
		function randomInt(mini, maxi){
        var nb = mini + (maxi+1-mini)*Math.random();
        return Math.floor(nb);
}

		function prechargerImg(){
		var position;
		tabImg = new Array(nombre_image);
		
		
		var tabPosition = new Array();
		for (i=0; i<=1 ; i++){
			tabPosition[i] = i;
		}
		
		for (i=2; i<=nombre_image -1; i++){
			do{
				position = 0;
				tabPosition[i] = (randomInt(2,nombre_image-1));
				for (j=2; j<=i; j++){
					if (tabPosition[i]==tabPosition[j]){
						position++;
					}
				}
			}while(position != 1);
		}
		
		for (i=0; i<=nombre_image -1; i++){
			tabImg[i]=new Image();
			tabImg[i].src = prefix_image+(1+tabPosition[i])+suffix_image;
		}
		}	

		function init()
		{
			img1 = document.getElementById("defilement1") ;
			img2 = document.getElementById("defilement2") ;
		
			prechargerImg();
			change_opacity();
		}

		function change_opacity()
		{	
			var opacity1 = 0 ;
			var opacity2 = 0 ;
			if (isIE)  // for IE
			{	opacity1 = parseFloat(img1.filters.alpha.opacity);
				opacity2 = parseFloat(img2.filters.alpha.opacity);
			}
			else       // for mozilla
			{	opacity1 = parseFloat(img1.style.opacity);
				opacity2 = parseFloat(img2.style.opacity);
			}

			if (sens)
			{	if (isIE)  // for IE
				{	img1.filters.alpha.opacity = opacity1 + coef * 100;
					img2.filters.alpha.opacity = opacity2 - coef * 100;
				}
				else // for Mozilla
				{	img1.style.opacity = opacity1 + coef;
					img2.style.opacity = opacity2 - coef;
				}
			}
			else
			{
				if (isIE)  // for IE
				{	img1.filters.alpha.opacity = opacity1 - coef * 100;
					img2.filters.alpha.opacity = opacity2 + coef * 100;
				}
				else // for Mozilla
				{	img1.style.opacity = opacity1 - coef;
					img2.style.opacity = opacity2 + coef;
				}
			}

			if (isIE)  // for IE
			{	opacity1 = parseFloat(img1.filters.alpha.opacity);
				opacity2 = parseFloat(img2.filters.alpha.opacity);
			}
			else       // for mozilla
			{	opacity1 = parseFloat(img1.style.opacity);
				opacity2 = parseFloat(img2.style.opacity);
			}
		
			// on fait varier le sens d'opacite du bazar
			if (opacity2  <= 0)
			{	img2.src=tabImg[indice++].src;
				sens = 0;
				if (indice == (tabImg.length)) indice=0;
				window.setTimeout("change_opacity()",temps_pause) ; // attente
				return 0;
			}
			else if (opacity1 <= 0)
			{	img1.src=tabImg[indice++].src;
				sens = 1;
				if (indice == (tabImg.length)) indice=0;
				window.setTimeout("change_opacity()",temps_pause) ; // attente
				return 0;
			}
			window.setTimeout("change_opacity()",temps) ; // recursion toutes les x millisec
		}