private void btnRoomManagement_Click(object sender, RoutedEventArgs e)
{
this.Hide();
RoomManagement roommanagement = new RoomManagement();
roommanagement.Show();
}
private void btnRoomManagement_Click(object sender, RoutedEventArgs e) //
{
RoomManagement mgmtWindow = new RoomManagement();
mgmtWindow.Show();
this.Close();
}