ASP.NET

private void bounddropdownlist()
    {
        string query = "select CouponName,CouponTypeID from CouponType";
        DAL Helper = new DAL();
        Helper.ConnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
        ds = new DataSet();
        ds = Helper.ExecuteDataSet(CommandType.Text, query, null);
        ddlCType.DataValueField = "CouponTypeID";
        ddlCType.DataTextField = "CouponName";
        ddlCType.DataSource = ds;
        ddlCType.DataBind();
    }

protected void btnSubmit_Click(object sender, EventArgs e)
    {
        try
        {
            ErrorMessage.Text = "";
        
string query = "insert into CouponTransaction(CouponTypeID,TransactionDate,TransactionTypeID,Description,CafeMenu,SerialStart,SerialEnd,Price,

TotalSale)values('" + ddlCType.SelectedValue.ToString() + "','"+ TxtbxDate.Text 

+"','"+ddlTtype .SelectedValue .ToString ()+"','"+TxtDes .Text +"',

'"+ddlMenu .SelectedValue+"','"+txtSFrom .Text +"','"+TxtEnd .Text +"','"+Txtprice .Text  +"','"+TxtSale .Text +"')";

DAL helper = new DAL();
            helper.ConnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
            int result = helper.ExecuteNonQuery(CommandType.Text, query, null);
            if (result == 1)
                ErrorMessage.Text = "Records inserted successfully";
            else
                ErrorMessage.Text = "Records could not be inserted";
            cnx.Close();
        }
        catch (Exception ex)
        {
            ErrorMessage.Text = ex.Message;
        }
    }