private void btnEditSelectedEmpl_Click(object sender, EventArgs e)
{
if (listViewEmployee.SelectedItems.Count == 0)
{
MessageBox.Show("Please select employee.");
return;
}
AddEmployee aef = new AddEmployee(em, (Employee)listViewEmployee.SelectedItems[0].Tag);
aef.FormClosed += new FormClosedEventHandler(AddEmployee_Closed);
aef.ShowDialog();
}