How to Silence an incoming call in Samsung GURU E1080 mobile?

Samsung GURU cellphones do have an option to silence an incoming call in normal profile, just like how nokia provides a 'Silence' option on screen. However, this text 'silence' is not visible in samsung guru screen and is also not documented.

To silence an incoming call just press the Down arrow key on navigation button for 2 seconds.
Next time when a call is received, the phone will ring with original volume.
You can also consecutively press the down arrow button to reduce the ringer volume of incoming call.