public void Delete(int POId)
{
QuickReceiptEntities ctx = new QuickReceiptEntities();
var existingPO = (from p in ctx.PurchaseOrders
where p.POId == POId
select p).FirstOrDefault();
if (existingPO == null)
{
throw new ObjectNotFoundException("Purchase Order with POId " + POId + "couldn't be found int the database. No deletion was performed.");
}
ctx.DeleteObject(existingPO);
ctx.SaveChanges();
}