function openPopup(fenetre){
	// affichage du popup
	document.getElementById(fenetre).style.display = "block";
	// masquage des elements select de la page (bug IE 6)
	var elemSel = document.getElementsByTagName("select"); 
	for (var i=0; i < elemSel.length; i++) elemSel[i].style.visibility="hidden";
}

function closePopup(fenetre){
	// masquage du popup
	document.getElementById(fenetre).style.display = "none";
	// affichage des elements select de la page (bug IE 6)
	var elemSel = document.getElementsByTagName("select"); 
	for (var i=0; i < elemSel.length; i++) elemSel[i].style.visibility="visible";
}