Active Directory - Group Issue

Sub AddUserToAGroup(ByVal GroupName As String, ByVal UserCN As String)

            Dim dirEntry As New DirectoryEntry
            dirEntry.Path = "LDAP://OU=Some_Site,DC=Domain,DC=NET"
            dirEntry.Username = sADUsername
            dirEntry.Password = sADPassword


            If UserExists(UserCN) = True Then

                Dim group As DirectoryEntry = dirEntry.Children.Find("CN=" & GroupName, "group")
                Dim usr As DirectoryEntry = group.Children.Find("CN=" & UserCN, "user")

                If group IsNot "" Then
                    group.Properties("member").Add(usr.Properties("distinguishedName").Value)
                    group.CommitChanges()
                End If
            ElseIf UserExists(UserCN) = False Then
                Exit Sub
            End If
        End Sub