Clicking on New event will open the New event window.
Here you can enter all the details for the event, set start and end dates and select invitees/groups.
Clicking on Select invitees allows you to select visitors from the list and add them to the event, and clicking on Add invitees by group allows you to select groups to add to the event.
CardExchange Solutions Support Team
"If you define the problem correctly, you almost have the solution." (Steve Jobs)