CELKO (10/2/2012)
...NO! We hate UDFs; they are not declarative, do not optimize ...
Nonsense. The OP has explained that (s)he is a novice, Joe, and is willing to learn or wouldn't be contributing on this thread. Feeding new pupils with dogma is unethical and unprofessional. You're wrong about optimisation too - iTVF's are subbed into the plan just like a view. Look no further than the two articles by Paul White referenced in my signature block.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden