function switchDisplay(obj_name) {
	if(obj_name!='') obj=document.getElementById(obj_name);
	if(obj)
		if(obj.style.display=="block")
			obj.style.display="none";
		else
			obj.style.display="block";
}


function popup(page, nom, l, h, scrollbars) {
    // centrer le popup dans l'écran
	var PosX = ( screen.availWidth - l ) / 2;
	var PosY = ( screen.availHeight - h ) / 2;
	return window.open(page, nom, "top="+PosY+",left="+PosX+",width="+l+",height="+h+",scrollbars="+scrollbars);
}