cross site scripting issue with javascript code behind

We have scanned our site for vulnerabilities. We received a warning message on this code("StaticPostBackScrollVerticalPosition") for potential cross-site scripting.

What needs to be changed to fix this issue? Please let me know.

private const string VerticalPosition = "StaticPostBackScrollVerticalPosition";
private const string ScriptHidden = "document.forms[0].{0}.value";
private const string SaveScriptName = "StaticPostBackScrollPositionSave";
private const string LoadScriptName = "StaticPostBackScrollPositionLoad";

private const string ScriptGetPosition = ScriptHidden + " = (navigator.appName == 'Netscape') ? window.page{1}Offset : document.documentElement.scroll{2};";

private string GetPositionScript()
{
    StringBuilder sb = new StringBuilder();

    sb.Append("<script language=\"JavaScript\"> \n");
    sb.Append("function SaveScrollPosition() { \n");
    sb.AppendFormat(ScriptGetPosition , VerticalPosition, "Y", "Top");
    sb.Append("setTimeout('SaveScrollPosition()', 100);");
    sb.Append("} \n");
    sb.Append("SaveScrollPosition(); \n");
    sb.Append("</script> \n");
    return sb.ToString();
}

private void ScrollPosition()
{
    if (!this.ClientScript.IsStartupScriptRegistered(SaveScriptName))
    {
        this.ClientScript.RegisterClientScriptBlock(GetType(), SaveScriptName, GetPositionScript());
        this.ClientScript.RegisterHiddenField(VerticalPosition , "0");
    }
}