I have a column named clinic and enter a number there. The only problem is
that the number I enter can have different departments associated to them.
For example, if I put 88, it can be associated with Gen, Rad or Neuro.
There are only two numbers that are like this, 88 and 90, 90 has 2
departments it can be associated with. Otherwise, everything else is just a
one to one association.

I want to be able to create another column call description, which will
contain a drop down list. If either 88 or 90 is entered in the dept column,
I want the description column to list the possibilities.

Let me know if this is a good way to do it and how to do it. Of if you have
any other ideas.

Thank you