To have an IP phone (i.e. 7960) auto select a line when the phone goes off hook use the auto-line <line number> command under the ephone <num> configuration. The default behavior is to require a line to be selected .
ephone 1
mac-address 0014.4611.3573
auto-line 1
button 1:1 2:3 3:5
Press **#** to reset the Cisco IP Phone 7960, and the phone cycles through normal startup procedures.
To perform a soft reset of the phone if it has not registered with a CallManager you can hold down *+6+Settings and the phone should reboot.
To unlock and reset the network configuration go to “settings” (button with the square and a check mark through it) then hit 3 to go to “Network Configuration” and then press 33 to get to “Erase Configuration”. If the configuration is locked press **# to unlock it. Then you will see a “Yes” softkey enabled. Select “Yes” and then save.
To restore the phone back to the factory defaults follow the instructions:
Step 1 
Unplug the power cable from the phone and then plug it back in.
The phone begins its power up cycle.
Step 2 Immediately press and hold # while the Headset, Mute, and Speaker buttons turn on and off in sequence.
Release # after the Speaker button turns off.
The Headset, Mute, and Speaker buttons flash in sequence to indicate that the phone is waiting for you to enter the key sequence for the reset.
Step 3 Press 123456789*0# within 60 seconds after the Headset, Mute, and Speaker buttons begin to flash.
Step 4 Next the phone will display “Save network cfg? 1=yes 2=no”. Select 2 to erase the network configuration if needed. Finally the phone will display “Factory reset initiated” and boot up.
