Excel 2000: Windows XP:

I thought I could do this with the IF statement, but couldn't, and I do not
know programming. I have a spreadsheet with thousands of account numbers
listed in column "B" that are preceeded by a state (e.g., PA, NY, DE, etc.)
in Column "A". Likewise, there are similar state and account numbers in
columns "C" and "D". I need to know what accounts listed in columns "A" and
"B" are not listed in columns "C" and "D" and have the results listed
separately, say, columns "E" and "F".
--
Leo