saving negative forecast values

Hi DP gurus,

I wanted to know is there any way in which we can save negative forecast values in the batch/interactive mode.

One way which is see is using "Message 402: Forecast values will be negative". We can select this message while setting up Activity for batch run.

But still i am not able to see negative values in demand book.

Please suggest any other ways of achieving this, and also for interactive planning.

Thanks