How To Enable/Disable Do Not Disturb(DND)?

How To Enable/Disable Do Not Disturb(DND)?

Do Not Disturb(DND) is a function to prevent incoming calls from ringing the phone.

To Enable DND:
==============
There are two ways to enable DND:

1-Press the DND button on the phone
2-Dial *78

To Disable DND:
==============
There are two ways to disable DND:

1-Press the DND button on the phone
2-Dial *79