Access JavaScript Variable on Pageload Event in C#

//Javascript code
<script type="text/javascript" src="http://l2.io/ip.js?var=myip"></script>
  <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
   <script type="text/javascript" language="javascript">
   $(document).ready(function () {
      var queryString = window.location.search;
      if(queryString == "")
      {
            alert("Data inserted");
            window.location.href = "http://localhost:2305/WebSite66/Default.aspx?ip="+myip;
            return false;
      }
    });
   </script>

//C# Code
protected void Page_Load(object sender, EventArgs e)
{
    if (Request.QueryString["ip"] != "" && Request.QueryString["ip"] != null)
    {
        string ip = Request.QueryString["ip"].ToString();
        if (con != null && con.State == ConnectionState.Closed)
        {
            con.Open();
        }

        //Insert in database code

        if (con != null && con.State == ConnectionState.Open)
        {
            con.Close();
        }
    }
}