Microsoft JScript runtime error: Object expected

Here is my code:


<%@ Page Language="VB" AutoEventWireup="false" CodeFile="TrackingAdministration.aspx.vb" Inherits="TrackingAdministration"
EnableViewState = "false" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
   <script type="text/javascript" language="javascript">
   document.getElementById("trackingGridView").
   function test( sender)
 {
 //alert(sender);
 var arr = document.getElementById(sender).childNodes
 for( i = 0; i < arr.length; ++i)
 {
 if(arr[i].value == & ...