Finding a row in a dataset

[jachin]

I am trying to find a row in a datagrid to update my dataset but i keep getting the following error:
System.NullReferenceException: Object reference not set to an instance of an object.

Here is my code, the bold line is the line with the error:
Sub dgMembers_Update(s As Object, e As DataGridCommandEventArgs)
If Page.IsValid
Try
trace.write(dgMembers.DataKeys(e.Item.ItemIndex))
Dim objDR = objDS.Tables("tblMembers").DefaultView.Find(dgMembers.DataKeys(e.Item.ItemIndex)) objDR("Firstname") = CType(e.Item.FindControl("txtFirstname"), TextBox).Text
objDR("Lastname") = CType(e.Item.FindControl("txtLastname"), TextBox).Text
objDR("Email") = CType(e.Item.FindControl("txtEmail"), TextBox).Text
objDR("IsAdmin") = IIf(CType(e.Item.FindControl("ddlAdmin"), DropDownList).SelectedItem.Value = "1", true, false)
objDR("IsAdmin") = IIf(CType(e.Item.FindControl("ddlBanned"), DropDownList).SelectedItem.Value = "1", true, false)
' Update the dataset and database
objCB = New OleDbCommandBuilder(objDA)
objDA.Update(objDS, "tblMembers")
Catch objOleDbException As OleDbException
lblError.Text = "<p>" & objOleDbException.ErrorCode & "</p>"
lblError.Text += "<p>" & objOleDbException.Message & "</p>"
lblError.Text += "<p>" & objOleDbException.StackTrace & "</p>"
lblError.Visible = true
End Try

dgMembers.EditItemIndex = -1
BindData()
End If
End Sub

[Nawaz Ijaz]

Does the error message tell any row number ?
This error normally occur when u just take a reference and donot assign memory by calling constructor using New Operator.

Don't know where is the error, just check wether "objDA" has been assigned the memory.

objDA.Update(objDS, "tblMembers")