Help please....I am trying to compare data in 2 sheets to get the difference
from month to month

#1 (previous month's forecast)
Customer Part number Dollars
ABD 1234 $500

#2 (current month's forecast)
Customer Part number Prev Month $ Dollars Difference
ABD 1234 ?? $600
$100

I am trying to find a formula that would compare the 2 worksheets : if
customer & part number match from #1 to #2 then input the dollars from that
customer on #1 to same customer on #2. One problem I run into is that there
could be a customer or part number addition or subtraction from one month to
another.