private void button5_Click(object sender, EventArgs e)
{
btnMat2 lv2 = new btnMat2();
lv2.Show();
this.Close();
}
//int index;
//int[] ListIndexDaDung;
//int indexdadung;
private void btncaudung_Click(object sender, EventArgs e)
{
//ListIndexDaDung = new int[3];
btnMat2 mat2 = new btnMat2();
mat2.Show();
this.Close();
}