function afficheImagePopup(page,largeur,hauteur) {
  var options = 'menubar=no,scrollbars=no,statusbar=no'; 
  var top=(screen.height-hauteur)/2;     
  var left=(screen.width-largeur)/2;     
  window.open(page,"","top="+top+",left="+left+",width="+largeur+",height="+hauteur+","+options);
}