Hi Tan,
You can record your own greetings and can configure multiple greetings. These greetings fall into the following three categories:
•Standard greetings
•Alternate greetings
This category includes the following types of greetings:
–Alternate
–Meeting
–Vacation
–Extended absence
•State-based greetings:
This category includes the following types of greetings:
–Busy
–Closed
–Internal
By default, the standard greeting is enabled and none of the alternate or state-based greetings are enabled. The standard greeting is always enabled but if one of the alternate greetings is enabled, it takes precedence over the standard and state-based greetings.
You can enable one or all of the state-based greetings. These greetings are played when no alternate greeting is enabled and the following conditions apply:
•When the system is busy, the busy greeting is played. When enabled, the busy greeting has precedence over the other state-based greetings.
•During nonbusiness hours, the closed greeting is played.
•When the call is from an internal number, the internal greeting is played.
Except for the standard greeting, when you enable a greeting, you can also specify an end date for the greeting.
You can also perform the following actions for all of the greetings:
•Set the source of the greeting.
•Upload a greeting.
Set the source of the greeting to one of the following:
•System greeting
This greeting comes with the system and is made of system prompts.
•User recording
This greeting is recorded/uploaded by the user. It can be recorded whether or not it is enabled.
•None
This greeting is an empty greeting and can be selected if you want no greeting to be played.
Please refer the below links for configuration steps
http://www.cisco.com/en/US/docs/voice_ip_comm/unity_exp/rel3_1/online_help/gui/cmeadmin/admin/cueadcme.pdf
http://www.cisco.com/en/US/partner/products/sw/voicesw/ps5520/products_tech_note09186a008041d950.shtml
Hope this helps.
Tx,
Shalu