How can I get the conference ID which users need to call in from a lync conference programmatically?

I'm using the Lync SDK to schedule meetings on a Lync Server. Now I want the conference Id which users need to call in by phone. How can I get it programmatically?

When scheduling a meeting by using ConferenceServices.BeginScheduleConference I get the conference-object but the phoneinformation is null. When setting PhoneAccessEnabled true in the ConferenceScheduleInformation I get an error.

Has someone a hint for me?

The solution was an easy one. Setting PhoneAccessEnabled was the right thing. The error which occured was thrown because the passcode had numbers and letters in it what is really bad if you'll use a real phone. The passcode was created by ConversionServices.GeneratePasscode().

Now I use the Random-Class for creating a number-only passcode and it works.