You can use DND to reject incoming calls automatically on the phone. Callers will receive a busy message.

To activate DND in phone mode: 

1. Tap .
The  icon on the status bar indicates that DND is enabled. 

Incoming calls will be rejected automatically and n New Missed Call(s) ("n"  indicates the number of the missed calls) will appear on the touch screen.  

To deactivate DND in phone mode:

1. Tap  again.