I am getting "No Overload For Method 'Bind' takes '2' Arguments" under this line:

try
{
con.Bind(userDN, userPasswd);
}

Please help.Below is the full code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Net;
using System.Diagnostics;
using System.DirectoryServices.Protocols;
using System.DirectoryServices;




namespace edirectory_test_1
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
        {
            string userDN = "cn=proxy" + ",o=University";
            string userPasswd = "test101";
            LdapConnection con = new LdapConnection(new LdapDirectoryIdentifier("11.13.220.33:389"));
            con.Credential = new NetworkCredential(String.Empty, String.Empty);
            con.AuthType = AuthType.Basic;
            using (con)
            {
                try
                {
                    con.Bind(userDN, userPasswd);
                }
                catch (LdapException)
                {
                    lblResult.Text = "Invalid server address or admin password";
                    return;
                }
                catch (DirectoryOperationException)
                {
                    lblResult.Text = "Invalid admin username";
                    return;
                }
                try
                {
                    SearchRequest request = new SearchRequest("o=campus", "(&(objectClass=Person)(uid=" + Login1.UserName + "))", SearchScope.Subtree);

                    SearchResponse response = (SearchResponse)con.SendRequest(request);
                    if (response.Entries.Count == 0)
                    {
                        lblResult.Text = "No such username.";
                        return;
                    }
                    else
                    {
                        SearchResultEntry entry = response.Entries[0];
                        string dn = entry.DistinguishedName;
                        con.Credential = new NetworkCredential(dn, Login1.Password);
                        con.Bind();
                        // If we get this far without an exception, the username and
                        // password are valid. We can now use a SearchRequest to search
                        // for group membership etc, but that's out of scope for this
                        // example.

                        e.Authenticated = true;
                    }
                }
                catch (DirectoryOperationException)
                {
                    lblResult.Text = "Invalid root DN / search filter";
                    return;
                }
                catch (LdapException)
                {
                    lblResult.Text = "Invalid password";
                    return;
                }
                catch (Exception ex)
                {
                    // an LdapException is thrown if the password is invalid, with
                    // ex.Message == "The supplied credential is invalid.".
                    lblResult.Text = ex.Message;
                }
            }
        }
    }
}