error in bill view/Print summary

Question

Thanx for all the help guyz i appreciate, as i said earlier i am new to c# that is why i need your help with this project am working on.

 

I am trying to view bills and print summary but am getting this error, please help detect the problem.

 

Thanks

 

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace NSPM_Sales_Invoice
{
public partial class ViewBills : Form
{
SqlConnection con = new SqlConnection(Properties.Settings.Default.NSPM_Sales_InvoiceCon);
SqlCommand cmd;
SqlDataAdapter da;
DataTable dt;
public ViewBills()
{
InitializeComponent();
}
private void ViewBills_Load(object sender, EventArgs e)
{
con.Open();
da = new SqlDataAdapter("Select * from Tbl_HeaderData order by JobNo asc", con);
con.Close();
SqlCommandBuilder cb = new SqlCommandBuilder(da);
dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
}
private void btnViewBills_Click(object sender, EventArgs e)
{
con.Open();
da = new SqlDataAdapter("Select * from Tbl_HeaderData where JobNo between '" + dateTimePicker1.Value.ToString("yyyy-MM-dd") + "'and'" + dateTimePicker2.Value.ToString("yyyy-MM-dd") + "'order by JobNo asc ", con);
DataSet ds = new DataSet();
da.Fill(ds, "Tbl_HeaderData");
dataGridView1.DataSource = ds.Tables["Tbl_HeaderData"];
con.Close();
}
}
}