private void btnCreateConference_Click(object sender, EventArgs e)
{
if (index < rooms.Length)
{
rooms[index++] = new ConferenceRoom(rnd.Next(1, 101), rnd.Next(1, 11), rnd.Next(50, 101));
}
}
//copy constructor
public ConferenceRoom(ConferenceRoom c)
: this(c.RoomNumber, c.DaysOccupied, c.Area)
{ }