private void danhMụcHàngToolStripMenuItem_Click(object sender, EventArgs e)
{
if (dmh == null)
{
dmh = new DanhMucHangForm();
dmh.FormClosed += new System.Windows.Forms.FormClosedEventHandler(this.DanhMucHangForm_FormClosed);
dmh.MdiParent = this;
dmh.Show();
}
}
private void DanhMucHangForm_FormClosed(object sender, FormClosedEventArgs e)
{
dmh = null;
}