function popunder() {

window.open ('lettre.htm', 'popunder','resizable,width=488,height=340');

}

function popup(f, nom, w, h) {

window.open (f, nom, 'resizable,width=' + w + ',height=' + h)

}

function popup2(f, nom, w, h) {

window.open (f, nom, 'resizable,scrollbars=yes,width=' + w + ',height=' + h)

}