public void AddServiceLink(int PreID, string lsID)
 {
     var ls = lsID.Split(',');
     foreach (var item in ls)
     {
         var link = _db.PremiseLinkServices.Where(m => m.PremiseID == PreID && m.PremiseID.ToString() == item).SingleOrDefault();
         if (link == null)
         {
             var ser = _db.Services.Where(m => m.SerID.ToString() == item).SingleOrDefault();
             if (ser != null)
             {
                 var newLink = new PremiseLinkService();
                 newLink.PremiseID = PreID;
                 newLink.ServiceID = ser.SerID;
                 _db.PremiseLinkServices.InsertOnSubmit(newLink);
                 _db.SubmitChanges();
             }
         }
     }
 }
 partial void DeletePremiseLinkService(PremiseLinkService instance);
 partial void UpdatePremiseLinkService(PremiseLinkService instance);
 partial void InsertPremiseLinkService(PremiseLinkService instance);
		private void detach_PremiseLinkServices(PremiseLinkService entity)
		{
			this.SendPropertyChanging();
			entity.Service = null;
		}
		private void attach_PremiseLinkServices(PremiseLinkService entity)
		{
			this.SendPropertyChanging();
			entity.Premise = this;
		}