Sheet1 named "Alignment" (contains alignment of our sales people):
---------------------------------------------------------------------------
Column A= Customer List of ID's
Column B= Salesperson 1 ("yes" in cells below if he has that customer)
Column C= Salesperson 2 ("yes" in cells below if he has that customer)
Column D= Salesperson 3 ("yes" in cells below if he has that customer)

Sheet2 named "Customer Listing":
---------------------------------------
Cell A1= drop-down selectable list of our sales people
When a salesperson is selected I need a list of all their customers to
appear on the sheet.

I would prefer to do this with formulas rather than code. I remember
reading somewhere a while back that with dynamic ranges and maybe the
Offset(?) function this could be done formulaically. Is that possible?