ดู code นี้ให้ผมหน่อยครับ เกี่ยวกับปุ่ม Search ครับ มัน error Fill: SelectCommand.Connection property has not been initialized.

 public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        SqlConnection conn;
        SqlCommand comm;
        string sqlstr;
        private void frmsearch_Load(object sender, EventArgs e)
        {
            //ติดต่อฐานข้อมูล
            string strconn = Class1.strconn;
            conn = new SqlConnection();
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
            }
            conn.ConnectionString = strconn;
            conn.Open();
            //-----

            DataSet ds = new DataSet();
            SqlDataAdapter da = new SqlDataAdapter();

            sqlstr = "select * from FACULTY";
            comm = new SqlCommand(sqlstr, conn);
            da.SelectCommand = comm;
            da.Fill(ds, "tmp");

            comboBox1.DataSource = ds.Tables["tbm"];
            comboBox1.DisplayMember = "FNAME";
            comboBox1.ValueMember = "FNAME";
            comboBox1.SelectedIndex = 0;

        }

Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click

        If txtSearch.Text = "" Then Exit Sub

        If IsNumeric(txtSearch.Text) = False Then
            MessageBox.Show("กรุณาป้อนข้อมูลที่เป็นตัวเลขเท่านั้น !!!", "ข้อผิดพลาด", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtSearch.Focus()
            txtSearch.SelectAll()
            Exit Sub
        End If

        Dim sqlSearch As String = ""
        Dim tmpNetPaid As Single = 0

        sqlSearch = "SELECT Agent.Agent_Name, Agent.Agent_Address,"
        sqlSearch &= " Agent.ContactName, Agent.Agent_Tel,"
        sqlSearch &= " Order.OrderID, Order.Order_Netpaid,"
        sqlSearch &= " OrderDetail.EquipmentID, Equipment.Equip_name,"
        sqlSearch &= " OrderDetail.Order_Num,BookOrder.Order_ReceivedDate,"
        sqlSearch &= " Order.IsReceived,Order.IsNormal "
        sqlSearch &= " FROM Equipment, OrderDetail, Agent, Order"
        sqlSearch &= " WHERE (Equipment.EquipmentID = OrderDetail.EquipmentID)"
        sqlSearch &= " AND (Equipment.AgentID = Agent.AgentID)"
        sqlSearch &= " AND (OrderDetail.OrderID = Order.OrderID)"
        sqlSearch &= " AND (Order.OrderID='" & txtSearch.Text & "')"
        sqlSearch &= " AND (Order.IsReceived='0')"
        sqlSearch &= " AND (Order.IsNormal='1')"
        sqlSearch &= " ORDER BY OrderDetail.EquipmentID"

        If IsFind = True Then
            ds.Tables("Search").Clear()
        End If

        da = New SqlDataAdapter(sqlSearch, Conn)
        da.Fill(ds, "Search")

        If ds.Tables("Search").Rows.Count <> 0 Then
            IsFind = True

            lblAgentName.Text = CStr(ds.Tables("Search").Rows(0).Item("Agent_Name"))
            lblAddress.Text = CStr(ds.Tables("Search").Rows(0).Item("Agent_Address"))
            lblContactName.Text = CStr(ds.Tables("Search").Rows(0).Item("ContactName"))
            lblTel.Text = CStr(ds.Tables("Search").Rows(0).Item("Agent_Tel"))
            tmpNetPaid = CSng(ds.Tables("Search").Rows(0).Item("NetPaid"))
            lblNetPaid.Text = tmpNetPaid.ToString("#,##0.00")

            With grdEquipmentOrder
                .AllowNavigation = False
                .ReadOnly = True
                .DataSource = ds.Tables("Search")
            End With
        Else
            IsFind = False
            ClearAllData()
            grdEquipmentOrder.DataSource = Nothing
            MessageBox.Show("หมายเลขใบสั่งซื้อที่คุณระบุไม่มี หรือได้รับอุปกรณ์ไปแล้ว !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Information)
            txtSearch.Focus()
            txtSearch.SelectAll()
        End If

        FormatDataGridWithData()
    End Sub