//--------------menage nannis----------------//
/// <summary>
/// adds a nanny to the data base
/// Exception:
/// in the data base is are a nanny with the same ID
/// </summary>
/// <param name="nan">nanny object to add</param>
public void addNanny(Nanny nan)
{
var check = (from nanny in DataSourceXml.NannyRoot.Elements()
where (Convert.ToInt32(nanny.Element("Id").Value)) == nan.Id
select nanny).FirstOrDefault();
if (check == null)
{
DataSourceXml.NannyRoot.Add(nan.Clone().NannyToXml());
DataSourceXml.saveNannis();
}
else
{
throw new Exception("There is the same nanny already");
}
}
