var i=1 
   var max = 100;     
   var min = 0;     
   var opacite=min;     
   up=true;     
   var IsIE=!!document.all;     
        
// préchargement des images   
photo1 = new Image();     
photo1.src = "Template/Photos_presentation/photo1.gpg";     
photo2 = new Image();     
photo2.src = "Template/Photos_presentation/photo2.gpg";     
photo3 = new Image();     
photo3.src = "Template/Photos_presentation/photo3.gpg";     
photo4 = new Image();     
photo4.src = "Template/Photos_presentation/photo4.gpg"; 
     
     
     
setInterval(augmenteopacity,60);    
var j=0;    
function augmenteopacity(i)     
{     
    j++;    
    if (j>20)  
    {    
if (document.getElementById("diapo"))
{
   var diapo = document.getElementById("diapo");     
     
if (opacite<max && up){opacite=opacite+2;}     
if (opacite>min && !up){opacite-=2;}     
if (opacite>=max){up=false;}     
if ((opacite<=min)){     
up=true;     
this.i=this.i+1;     
diapo.setAttribute("src","Template/Photos_presentation/photo"+this.i+".jpg");     
if (this.i>4) this.i=1;     
}
else diapo.setAttribute("src","Template/Photos_presentation/photo"+this.i+".jpg");     
     
IsIE? diapo.style.filter = "alpha(opacity=" + opacite + ")" : document.getElementById("diapo").style.opacity=opacite/100;     
}
}
}