Error:Permission denied in IExploer with XP service pack 2

[Jordan]

When I run this code in IExploer with XP sp2 and click on LinkButton
javascript bellow fire error: Errorermission error on row
!!!!!!!!!!!!.
And same code work fine after comment row **********.

It's work with Opera and FireFox.

Code behind

public class test : Page
{
protected LinkButton LinkButton1;

private void Page_Load(object sender, EventArgs e)
{
if(vPSession.User == null)
{
if(Request.Params["user"]!= null)
{
vPSession.User = new
User(Convert.ToInt64(Request.Params["user"]));
Response.Redirect(Request.Url.AbsolutePath);
}
else
{
string queryStr = "?";
queryStr += "ProductLink=" +
Server.UrlEncode(Request.Url.AbsoluteUri);
queryStr += "&Company=" +
Server.UrlEncode(ConfigurationSettings.AppSettings["CompanyName"]);
// vPSession.User = new User(2);
************** Response.Redirect(
ConfigurationSettings.AppSettings["vPassport"]+queryStr
);
}
}
}
override protected void OnInit(EventArgs e)
{
InitializeComponent();
base.OnInit(e);
}
private void InitializeComponent()
{
this.LinkButton1.Click += new EventHandler(this.LinkButton1_Click);
this.Load += new EventHandler(this.Page_Load);

}
private void LinkButton1_Click(object sender, EventArgs e)
{
Response.Write("Test!!!!!");
}
</P>

Client side html.



<script language="javascript">
<!--
function __doPostBack(eventTarget, eventArgument) {
var theform;
if (window.navigator.appName.toLowerCase().indexOf("netscape") > -1)
{
theform = document.forms["Form1"];
}
else {
!!!!!!!!!!!!!!! theform = document.Form1;
}
theform.__EVENTTARGET.value = eventTarget.split("$").join(":");
theform.__EVENTARGUMENT.value = eventArgument;
theform.submit();
}
// -->
</script>