function clearFieldEmail (field)
{
  fieldValue = field.value;
  //alert(fieldValue);
  if (fieldValue == "adresse e-mail")
    field.value = "";
  return false;
}

function toggleDiv (divToDisplay)
{
  if (oldDiv)
    $(oldDiv).style.display = 'none';
  oldDiv = divToDisplay;  
  $(divToDisplay).style.display = 'block';
}