gistfile1.cs

       private ICommand CreateCommand(DAOAction action)
       {
			if(action != DAOAction.Insert)
			{
				return new RelayCommand<IFormViewModel<T>>(vm =>
				{
					vm.Action = action;
					OnRequestOpenNew(vm);
				}, 
				vm => vm != null);
			}
       		
		   return new RelayCommand<IFormViewModel<T>>(v =>
       					{
       						var vm = (IFormViewModel<T>)GetNewEntityFormVM();
       						vm.Action = action;
       						OnRequestOpenNew(vm);
       					});
       }