private void cboLoadDrug_SelectedIndexChanged(object sender, EventArgs e)
{
// selectClass.SelectDrug(textBox5.Text.Trim());
selectClass.SelectDrug(cboLoadDrug.SelectedItem.ToString());
textBox6.Text = selectClass.DrugPrice.ToString();
selectClass.selectDrugQty(cboLoadDrug.SelectedItem.ToString());
getQty.Text = selectClass.drugQty.ToString();
}