do it with the datatable
VB Code:
  1. Dim cn As New SqlConnection("user id=sa;password=password;initial catalog=northwind")

  2.    Dim da As New SqlDataAdapter()

  3.    Dim dt As New DataTable()

  4.    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

  5.       cn.Open()

  6.       da.SelectCommand = New SqlCommand("select * from territories", cn)

  7.       da.Fill(dt)

  8.  
  9.       DataGrid1.DataSource = dt

  10.    End Sub

  11.  
  12.    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

  13.       Dim r As DataRow = dt.NewRow

  14.       dt.Rows.Add(r)

  15.    End Sub