void XoaForm(bool t)
{
if (t)
{
txtMaMon.Text = MonBUS.LayMaMonLonNhat();
txtDonGia.Text = txtTenMon.Text = string.Empty;
cboLoaiMon.SelectedValue = -1;
picHinh.Image = null;
}
else
{
txtMaMon.Text = txtDonGia.Text = txtTenMon.Text = string.Empty;
cboLoaiMon.SelectedValue = -1;
picHinh.Image = null;
}
}