Places the current call on hold.
Lets you place another call while the first call is on hold. This button replaces the Hold button when a call is on hold.
Opens the Dial Pad so you can manually dial additional numbers.
Dials any extra digits (such as a password or extension) that you assigned to a Speed Dial favorite button. This button replaces the Dial Pad button during outbound calls to numbers that include predefined extra digits. See “Defining favorite buttons” on page 56 for information on creating a Speed Dial favorite button.
Mutes the Treo microphone so that you cannot be heard.
Ending a call
Do one of the following:
•Press Power/End. 
.
•Select Hang Up.
•Press the headset button (if the headset is attached).
Returning to an active call from another application
You can use many other applications on your smartphone while holding a phone conversation, including the organizer and text messaging (SMS) features. You cannot browse the web or send and receive email while on an active call.
• From any application, press Phone/Send 
to return to the Active Call View.
When a call lasts longer than one minute, the screen turns off. Press any key except Power/End to wake up the screen, and then press Power/End to hang up the call. Be careful not to press Power/End to wake up the screen because this will accidentally end the call.