function openwin(url,name,width,height) {
	
	//taille de l'écran
    largeurEcran = screen.availWidth;
    hauteurEcran = screen.availHeight;
    
    //position de la fenetre pour centrage
    vertical = (hauteurEcran-height)/2;
    horizontal = (largeurEcran-width)/2 ;

	//var option = "toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=1,resizable=1,width=" + width +",height="+ height;
	var option = "toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=1,resizable=1,width=" + width + ",height=" + height + ",top=" + vertical + ",left=" + horizontal;
	window.open(url,name,option);
}