// mettre un minimum de 4 images !!!
var coef = 0.03 ; // avancement de l'opacité
var temps = 50 ; // temps entre chaque changement d'opacité
var temps_pause = 5000 ; // temps d'attente entre 2 changements d'images
var nombre_image = 17 ; // nombre d'images a faire bouger
var prefix_image = 'diaporama/visuel'; // chemin + prefix du nom des images
var suffix_image = '.jpg' ; // 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
var imagetest;
var imagetest_BIG;
var emplacementGrand;
var emplacementPetit;


function prechargerImg(){
tabImg = new Array(nombre_image);
for (i=0; i<=nombre_image -1; i++){
tabImg[i]=new Image();
tabImg[i].src = prefix_image+(i+1)+suffix_image;

}
}
function init()
{
img1 = document.getElementById("image1") ;
img2 = document.getElementById("image1_2") ;
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 varié le sens d'opacité 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


if (opacity1 <= 0.5 || opacity2 >= 0.5)
{
imagetest = "image1_2";
imagetest_BIG = "image1_2_BIG"
emplacementPetit = document.getElementById(imagetest).src;
tableau = emplacementPetit.split("diaporama") 
emplacementGrand = "diaporama_BIG" + tableau[1];

document.getElementById(imagetest_BIG).href = emplacementGrand;
clik = document.createAttribute("onClick");
clik.nodeValue = "return enlarge(emplacementGrand,event)";
document.getElementById(imagetest_BIG).setAttributeNode(clik);
}
if (opacity1 >= 0.5 || opacity2 <= 0.5)
{
imagetest = "image1";
imagetest_BIG = "image1_BIG"
emplacementPetit = document.getElementById(imagetest).src;
tableau = emplacementPetit.split("diaporama") 
emplacementGrand = "diaporama_BIG" + tableau[1];

document.getElementById(imagetest_BIG).href = emplacementGrand;
clik = document.createAttribute("onClick");
clik.nodeValue = "return enlarge(emplacementGrand,event)";
document.getElementById(imagetest_BIG).setAttributeNode(clik);
}
}