I have a problem with auto attendant in OS7030, v4.40.

When the outside caller ring to the system , will listen to the following message " welcome to .. if you want to talk with Accounting please press 1,or press 0 for assistant ".

The outside caller have three a possibilities as follow :

1)Outside Caller listen to the message then hang up the call, without dialing any number .

In this case, the auto attendant port will be busy,for one minute then will be free .

2)Outside Caller listen to the message,then press 1 to talk with
Accounting then hang up the call before the Agent answer the call .

In this case, the auto attendant port will be busy,for one minute then will be free .

3)Outside Caller listen to the message,then press 1 to talk with Accounting then the Agent answer the call .

In this case, no problem with auto attendant port .

The reverse polarity is enabled on All external lines (CO) .

Please I need help in the programming of Auto attendant, to programming auto attendant port to become free when the Outside Caller hang up the call .