Assistance
List and Manage Listeners of room
DnD (Drag & Drop) to push label into cells Alert Count Button Send Mail with Count of People via a mailTo protocol
Utilisation
add a person by enter a pseudo or is name, of course, in the input and by clicking the plus button. to delete this person you could drag the label and drop it on the minus button or by entering his name in the input text and clicking the minus button
To count people in the plan click on the sum symbol and an alert display the number of people. To mail this result click on the mail icon(mailto). In the clipboard an image of the plan must be in it (in chrome it's, but others navigators...)