Web form:

Code:
<form id="form1" runat="server">
    <div>
        <asp:TextBox ID="txtBxEmail" runat="server"></asp:TextBox>
        <asp:TextBox ID="txtBxPassword" runat="server"></asp:TextBox>
        <asp:Button ID="btnLogin" runat="server" Text="Login" OnClick="btnLogin_Click" />
        <br /><br />
        <asp:TextBox ID="txtBxLink" runat="server" Text="http://example.com/elements/13579642/"></asp:TextBox>
        <asp:Button ID="btnDisplay" runat="server" Text="Display" OnClick="btnDisplay_Click" />
        <br /><br />
        <asp:TextBox ID="txtBxSource" runat="server" TextMode="MultiLine" Width="600" Height="600"></asp:TextBox>
    </div>
</form>
Code behind:

Code:
protected void Page_Load(object sender, EventArgs e)
    {

    }

    CookieContainer loginCookie;

    public void btnLogin_Click(object sender, EventArgs e)
    {
        string postData = "type=0&user=" + txtBxEmail.Text + "&password=" + txtBxPassword.Text + "&remember=0";
        CookieContainer tempCookies = new CookieContainer();
        UTF8Encoding encoding = new UTF8Encoding();
        byte[] byteData = encoding.GetBytes(postData);

        HttpWebRequest postReq = (HttpWebRequest)WebRequest.Create("http://example.com/ajax/login.ajax.php");
        postReq.Method = "POST";
        postReq.KeepAlive = true;
        postReq.CookieContainer = tempCookies;
        postReq.ContentType = "application/x-www-form-urlencoded";
        postReq.Referer = "http://example.com/ajax/login.ajax.php";
        postReq.UserAgent = "Opera/9.80 (Windows NT 6.1; U; en) Presto/2.10.229 Version/11.61";
        postReq.ContentLength = byteData.Length;

        Stream postreqstream = postReq.GetRequestStream();
        postreqstream.Write(byteData, 0, byteData.Length);
        postreqstream.Close();
        HttpWebResponse postresponse = null;

        postresponse = (HttpWebResponse)postReq.GetResponse();
        tempCookies.Add(postresponse.Cookies);
        loginCookie = tempCookies;
        StreamReader postreqreader = new StreamReader(postresponse.GetResponseStream());
    }

    public void btnDisplay_Click(object sender, EventArgs e)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(txtBxLink.Text);
        request.CookieContainer = loginCookie;
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader reader = new StreamReader(response.GetResponseStream());
        string linkSourceCode = reader.ReadToEnd();

        txtBxSource.Text = linkSourceCode;
    }
You have to be logged in to see http://example.com/elements/13579642/[ sub page. When clicking the Display button it should populate txtBxSource with the elements source code, but it doesn't. Instead it shows the http://example.com/home/ source code. If I move the whole code in public void btnLogin_Click everything works, otherwise it doesn't.

1. What would be the solution for my problem?

2. Once I get it to work if I put the whole thing on a website/web host and someone logs (via this web page) in the http://example.com/ website and uses this mini application, the http://example.com/ website will receive his own IP or the webhost IP?