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

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer_opac * speed));
            timer_opac++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer_opac * speed));
            timer_opac++;
        }
    }
}

//change the opacity for different browsers, opacity from 0 to 100
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100); //new_official
    object.MozOpacity = (opacity / 100); //mozilla
    object.KhtmlOpacity = (opacity / 100); //konqueror
    object.filter = "alpha(opacity=" + opacity + ")"; //IE
}


/* OPACITY FOR LOGIN */
function inlogin(idbox) {

  //window.scrollTo(0,0) //retour en haut de la page

  /* on d�tecte la largeur de fen�tre */
  var larg = document.body.clientWidth + 20;
  var loginobject = document.getElementById("filter");
  loginobject.style.height="2000px";
  loginobject.style.width=larg+"px";

  /* on affiche le filtre */
  changeOpac(50,"filter")
  loginobject.style.display = "block";

  /* on d�sactive le scroll */
  //var htmlElement = document.getElementsByTagName('html')[0];
  //htmlElement.style.overflow = 'hidden'
  
  /* on affiche la popup correspondante */
  var popup = document.getElementById(idbox);
  popup.style.display = "block";
  
}

function outlogin(idbox) {
  /* on enleve la popup correspondante */
  var popup = document.getElementById(idbox);
  popup.style.display = "none";
  
  /* on enleve le filtre */
  var loginobject = document.getElementById("filter");
  changeOpac(50,"filter")
  loginobject.style.display = "none";
  
  /* on r�active le scroll */
  var htmlElement = document.getElementsByTagName('html')[0];
  htmlElement.style.overflow = 'auto';
}