Samsung BHM3100 - Manual (Page 18)

16
Press the Multi-Function button twice to redial the last number of the other phone,
see page 12.
Depending on the phone, pressing the Multi-Function button will display call history
instead of redialling.
Dialling.a.number.by.voice
Press and hold the Multi-Function button and say a name. You can dial a number
of the first phone.
Available call functions may vary by the phone.
Answering.a.call
Press the Multi-Function button to answer a call when you hear incoming call
tones.
When two calls from the two connected phones come in, you can answer the call
of the first phone.
Ending.a.call
Press the Multi-Function button to end a call.