if ((navigator.appName == "Netscape") && ((parseInt(navigator.appVersion) == 4) || (parseInt(navigator.appVersion) == 5))) {
  document.write("<link rel='stylesheet' href='css/firefox.css' type='text/css'>");
} else {
  document.write("<link rel='stylesheet' href='css/ie.css' type='text/css'>");
}
/***************/
function popupcentree(page,largeur,hauteur,options) {
	var top=(screen.height-hauteur)/2;
	var left=(screen.width-largeur)/2;
	window.open(page,"","top="+top+",left="+left+",width="+largeur+",height="+hauteur+","+options);
}