I have a list set up as follows:

ID# COMP PROF# YOE
12345 ACCOUNTANT 1 3
12345 SYS ANALYST 1 5
12345 CONTROLLER 1 8
12345 IT SPECIALIST 2 4
12345 WEB DESIGNER 2 1
23459 ACCOUNTANT 1 10
12450 ACCOUNTANT 1 3
12223 PROGRAMMER 1 3
12223 DENTIST 1 4

Here is the problem. I need to identify each ID number that has prof=1 when
there is more than one occurance of prof=1 in a single list. I have tried a
number of things such as the advanced filter on the prof field which gives me
all IDs set to 1. I only want IDs set to 1 that have more than one occurance
of prof=1.