function $(e)
{
	return document.getElementById(e);
}

function effacer(o, v)
{
	if(o.value == v)
		o.value = '';
}

function restaurer(o, v)
{
	if(o.value == '')
		o.value = v;
}

function envoyer(f)
{
	var form = $(f);
	form.submit();
}