private void btn_edit_Click(object sender, EventArgs e)
{
curr_index = listBox1.SelectedIndex;
TeacherAddEditForm tc_add = new TeacherAddEditForm(this);
tc_add.Owner = this;
tc_add.ShowDialog();
}
private void btn_add_Click(object sender, EventArgs e)
{
curr_index = -1;
TeacherAddEditForm tc_add = new TeacherAddEditForm(this);
tc_add.Owner = this;
tc_add.ShowDialog();
}