Active Directory/LDAP :: Using Directory Entry Of System.Directoryservices Class?

I am using Directory entry of System.Directoryservices class of Asp.net for authenticating against Sunone LDAP server. The following works fine.

DirectoryEntry entry = new DirectoryEntry("LDAP://SunOne2:42028/dc=domain,dc=com");
entry.AuthenticationType = AuthenticationTypes.None;
entry.Username = "uid=thost,ou=people,dc=domain,dc=com";(replaced original values)
entry.Password = password;
entry.RefreshCache();

Now I want to be able to authenticate all the users of different organisation units. e.g. ou=development,ou=accounting etc., So I specified like this, entry.Username = "uid=thost,ou=people,ou=devlopment,ou=accounting, dc=domain,dc=com"; but it says "There is no such object on the server". I also tried putting ou in URL. I am not sure where should I specify this OUs to make my search broad. I found a lot on internet but no success so far.