大家来找找这段程序的错误找错（来者有分呀！！！）

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace JYMaterMangerSystem

{

    public partial class Form2 : Form

    {

        SqlDataAdapter dapd;

        //SqlDataAdapter dast;

        //DataSet dsPd, dsStyle;

        data dt = new data();



        public Form2()

        {

            dapd = dt.Da("select * form JY_Material");

            InitializeComponent();

        }



        private void Form2_Load(object sender, EventArgs e)

        {  

           SqlCommandBuilder cm = new SqlCommandBuilder(dapd);

           dataGridView1.DataMember = "JY_Material";

           dgvhead();

        }

        void dgvhead()

        {

            dataGridView1.Columns[0].HeaderText = "编号";

            dataGridView1.Columns[1].HeaderText = "物料id";

            dataGridView1.Columns[2].HeaderText = "物料编码";

           // dataGridView1.Columns[0].ReadOnly = true;

            dataGridView1.Columns[3].HeaderText = "名称";

            dataGridView1.Columns[4].HeaderText = "规格";

            dataGridView1.Columns[5].HeaderText = "颜色";

            dataGridView1.Columns[6].HeaderText = "单位";

            dataGridView1.Columns[7].HeaderText = "生产厂家";

            dataGridView1.Columns[8].DefaultCellStyle.Format = "C";

            dataGridView1.Columns[8].HeaderText = "备注";

            //dataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;

        }

    }

}