private void button2_Click(object sender, EventArgs e)
        {
            Medicine_List a = new Medicine_List();

            if (textBox2.Text != string.Empty && textBox1.Text != string.Empty && textBox4.Text != string.Empty)
            {
                a.Name              = textBox2.Text;
                a.Manufacturer      = textBox1.Text;
                a.Retail_Price_Tk__ = float.Parse(textBox4.Text);
                h.Medicine_Lists.InsertOnSubmit(a);
                h.SubmitChanges();
                GridViewUpdate();
            }
            else
            {
                MessageBox.Show("Please insert all necessary Information !!!");
            }
        }
 partial void UpdateMedicine_List(Medicine_List instance);
 partial void DeleteMedicine_List(Medicine_List instance);
 partial void InsertMedicine_List(Medicine_List instance);