HTC Thunderbolt User Manual page 76

76 Phone calls
If
Display is off
You can also do one of the following to reject an incoming call:
Press the POWER button twice.

To reject the call and send a text message, press MENU, and then

tap Send message.
Changing the text message to send out for rejected calls
1. On the Phone dialer screen, press MENU.
2. Tap Settings > Edit default message.
3. Enter the new message, and then tap OK.
Muting the ringing sound without rejecting the call
Do one of the following:
Press the VOLUME DOWN or VOLUME UP button.

Press the POWER button.

Place the phone face down on a leveled surface.

If the phone is already facing down, the phone will still ring when there are
subsequent incoming calls.
To answer the call
When the Lock screen appears,
drag the bar that shows the caller
name or number downward.
To reject the call
Drag the bar upward.
Or, press MENU and then
tap Decline.