function init() {

  image1 = new Image();
  image1.src = "images/navigation/accueilon.jpg";
  image2 = new Image();
  image2.src = "images/navigation/accueiloff.jpg";
  image3 = new Image();
  image3.src = "images/navigation/contactoff.jpg";
  image4 = new Image();
  image4.src = "images/navigation/contacton.jpg";
  image5 = new Image();
  image5.src = "images/navigation/photooff.jpg";
  image6 = new Image();
  image6.src = "images/navigation/photoon.jpg";
  image7 = new Image();
  image7.src = "images/navigation/realisationoff.jpg";
  image8 = new Image();
  image8.src = "images/navigation/realisationon.jpg";
  image9 = new Image();
  image9.src = "images/navigation/serviceoff.jpg";
  image10 = new Image();
  image10.src = "images/navigation/serviceon.jpg";
  
  updateOpacity(document.getElementById('opacityDiv'),opacityVal);
  document.getElementById('opacityDiv').style.visibility = "visible";
  opacityEffect('opacityDiv');
}

function opacityEffect(divisionName) {
  if (opacityVal < 99){
    var division = document.getElementById(divisionName);
    opacityVal = opacityVal + 1;
    updateOpacity(division,opacityVal);
    setTimeout("opacityEffect('" + divisionName + "')",20);
  }
}

var opacityVal = 0;

function updateOpacity(imageobject, opacity){

  if (navigator.appName.indexOf("Netscape")!=-1 && parseInt(navigator.appVersion) >= 5)
    imageobject.style.MozOpacity = opacity/100;
  else if (navigator.appName.indexOf("Microsoft")!=-1 && parseInt(navigator.appVersion) >= 4)
    imageobject.style.filter = "alpha(opacity:" + opacity + ")";

}