Find "Speed dial setting"
Press Contacts.
Press the Contacts tab.
Press the Menu key.
Press More.
Press Speed dial setting.
Assign contact to speed dialling key
Press the required speed dialling key.
Speed dialling key 1 is for voicemail.
Press the required contact.
Speed dialling key 1 is for voicemail.
Exit
Press the Home key to return to standby mode.