private void LoadData()
{
ICollection <Gym> gyms = service.GetAllGyms();
GymComboBox.Items.Clear();
if (gyms != null)
{
foreach (Gym g in gyms)
{
GymComboBox.Items.Add(g.Name);
}
}
GymComboBox.SelectedIndex = -1;
GymComboBox.ResetText();
bindingSource1.DataSource = null;
}