public bool AddAccessUser(accessUser au)
 {
     try
     {
         db.accessUsers.InsertOnSubmit(au);
         db.SubmitChanges();
         return true;
     }
     catch (Exception error)
     {
         return false;
     }
 }
 //EDIT accessUser Table
 public int EditAccessUser(accessUser au)
 {
     try
     {
         var v = from i in db.accessUsers
                 where i.accessCode == au.accessCode
                 select i;
         accessUser newaccess = v.FirstOrDefault();
         if(newaccess != null)
         {
             newaccess = au;
             db.SubmitChanges();
             return 1;
         }
         return 0;//not found
     }
     catch (Exception error)
     {
         return -1;
     }
 }
 partial void DeleteaccessUser(accessUser instance);
		private void detach_accessUsers(accessUser entity)
		{
			this.SendPropertyChanging();
			entity.vahedInfo = null;
		}
 partial void UpdateaccessUser(accessUser instance);
 partial void InsertaccessUser(accessUser instance);
		private void attach_accessUsers(accessUser entity)
		{
			this.SendPropertyChanging();
			entity.userinfo = this;
		}