.NET Remoting problem

Hi,

I am new to using .net remoting and am attempting to write an application to process login's against Active Directory.  Currently I have the following code for my remote object:

using System;
using System.Text;
using System.Collections;
using System.DirectoryServices;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Http;

namespace ADRemote
{

///

public class ADRemote1 : MarshalByRefObject

private string _path;

private string _filterAttribute;

public ADRemote1()

//

// TODO: Add constructor logic here

//

public bool IsAuthenticated(string domain, string username, string pwd)

string domainAndUsername = domain + @"\" + username;

DirectoryEntry entry = new DirectoryEntry(_path, domainAndUsername, pwd);

try

//Bind to the native AdsObject to force authentication.

object obj = entry.NativeObject;

DirectorySearcher search = new DirectorySearcher(entry);

if(null == result)

return false;

//Update the new path to the user in the directory.

_filterAttribute = (string)result.Properties["cn"][0];

catch (Exception ex)

throw new Exception("Error authenticating user. " + ex.Message);

return true;

public string GetGroups()

DirectorySearcher search = new DirectorySearcher(_path);

StringBuilder groupNames = new StringBuilder();

try

int propertyCount = result.Properties["memberOf"].Count;

string dn;

int equalsIndex, commaIndex;

for(int propertyCounter = 0; propertyCounter < propertyCount; propertyCounter++)

dn = (string)result.Properties["memberOf"][propertyCounter];

if(-1 == equalsIndex)

return null;

catch(Exception ex)

throw new Exception("Error obtaining group names. " + ex.Message);

return groupNames.ToString();