Imports system.DirectoryServices
'-----------------------
 
 Dim group As New DirectoryEntry("LDAP://Domaincontroller01:389/CN=here the" & _
   "full distinguishedName of the group, DC=com")
 Dim user As New DirectoryEntry("LDAP://Domaincontroller01:389/CN=here the full" & _
 "distinguishedName of the user, DC=com")
 
 Dim isMember As Boolean = Convert.ToBoolean(group.Invoke("IsMember", New _
   Object() {user.Path}))
 
 
 If isMember Then
     Console.WriteLine("User {0} is already a member of the group", _
       user.Properties("cn").Value)
     '
     ' Remove the user from the group by invoking the remove method
     group.Invoke("Remove", New Object() {user.Path})
 Else
     Console.WriteLine("Adding the user to the group.")
     '
     ' Add the user to the group by invoking the Add method
     group.Invoke("Add", New Object() {user.Path})
 End If
 
 If Not IsNothing(user) Then
     user.Dispose()
 End If
 
 
 If Not IsNothing(group) Then
     group.Dispose()
 End If