Start by having a list of 100 people to do the job invitation for such time. Communication with at least 2 weeks in advance.By the sender of the message is the group that this meeting and made customizing days reply to know the true number of participants.
From the list of 100 people invited to participate in the day time. To communicate at least 2 weeks by the Messenger is the group that organized this conference. And the date of reply To truly know the number of participants.
starting from having a list of the 100 people. To invite attend in such days The communication at least 2 week .The sender is the group meeting, and define the reply to know the number of the participants truly .