private void button1_Click(object sender, EventArgs e)
        {
            Database_Class db = new Database_Class();

            int drug_num;
            int clinic_number    = 0;
            int quantity_stock   = 0;
            int reorder_lvl      = 0;
            int reorder_quantity = 0;


            string drug_name, drug_description, method_admin;
            double dosage, drug_cost;

            drug_name        = txtDrugName.Text;
            drug_description = txtDrugDescription.Text;
            method_admin     = txtMethodAdministration.Text;

            drug_num = Convert.ToInt32(txtDrugNum.Text);

            if (cmbQuantity_In_Stock.SelectedItem != null)
            {
                quantity_stock = int.Parse(cmbQuantity_In_Stock.SelectedItem.ToString());
            }

            if (cmbReorder_lvl.SelectedItem != null)
            {
                reorder_lvl = int.Parse(cmbReorder_lvl.SelectedItem.ToString());
            }

            if (cmb_Drug_Quantity.SelectedItem != null)
            {
                reorder_quantity = int.Parse(cmb_Drug_Quantity.SelectedItem.ToString());
            }

            if (cmbClinicNumber.SelectedValue != null)
            {
                clinic_number = int.Parse(cmbClinicNumber.SelectedValue.ToString());
            }


            dosage    = Convert.ToDouble(txtDosage.Text);
            drug_cost = Convert.ToDouble(txtDrugCost.Text);


            if (!txtDrugName.Text.Equals(null) || !txtDrugDescription.Text.Equals(null) || !txtMethodAdministration.Text.Equals(null) || cmbQuantity_In_Stock.SelectedItem != null || cmbReorder_lvl.SelectedItem != null || cmbClinicNumber.SelectedValue != null || cmb_Drug_Quantity != null || !txtDosage.Text.Equals(null) || !txtDrugCost.Text.Equals(null))
            {
                db.insert_pharma_supplies(drug_num, clinic_number, drug_name, drug_description, dosage, method_admin, quantity_stock, reorder_lvl, reorder_quantity, drug_cost);
                clear();
            }
            else
            {
                MessageBox.Show("Please enter all required information", "Pharmacutical Supplies", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }