Now this is a stab in the dark as it wasn't a well-formulated question so if I'm totally off topic for you I apologize.
If this is what your talking about when saying "three tier...", folow link below:
Quote:
The 3-tier architecture is usually known to have:
-Client Layer (GUI)
-Business Application Layer (Logic and Validations)
-Data Access Layer (queries /stored procedures)
Login system demonstrating 3-tier architecture[
^]
Please, should this not be what you are talking about, expand upon your question.
best regards
Frank