function ouvrirWindow(theURL,winName,features) { 
  newwindow=window.open(theURL,winName,features);
  newwindow.focus();
}

function popupcentree(page,largeur,hauteur,options) {
  var top=(screen.height-hauteur)/2;
  var left=(screen.width-largeur)/2;
  newwindow=window.open(page,"","top="+top+",left="+left+",width="+largeur+",height="+hauteur+","+options);
  newwindow.focus();
}