private void cb_supplier_DoubleClick(object sender, EventArgs e)
        {
            SupplierData sdata = new SupplierData();

            sdata.ShowDialog();
            txt_price.Text   = sdata.dataGridView1.CurrentRow.Cells[6].Value.ToString();
            cb_supplier.Text = sdata.dataGridView1.CurrentRow.Cells[1].Value.ToString();
        }
        public void txt_price_Click(object sender, EventArgs e)
        {
            SupplierData sdata = new SupplierData();

            sdata.ShowDialog();

            this.Text = sdata.PiceValue;
        }