Collections

Question

hi, I want help on Object collections I want to have a collections and on that collection I want to have sub collections. something like this (below) Microsoft (CertificationProvider Collection) |-----------MCP (Certification Collection) |-----------MCSA (Certification Collection) |-----------MCSE (Certification Collection) Cisco(CertificationProvider Collection) |-----------CCNA(Certification Collection) |-----------CNA(Certification Collection) Novel(CertificationProvider Collection) |----------NTT(Certification Collection) |----------NTNA(Certification Collection) pls give me a idea how to create something like this using collection. tks in advance.