private void button7_Click(object sender, EventArgs e)
{
frmDangKiDeTai f = new frmDangKiDeTai();
f.ShowDialog();
}
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
frmDangKiDeTai f = new frmDangKiDeTai();
f.ShowDialog();
}