I need to match a data point in a new report with the previous report and then pull in a note for that matching data point.

Each month I get a report have look at the data then make a note:
Column A:work number Column D:note made by me

The data changes some of the data in A: drops off which then would make note in column D: unimportant for the current report.

I played around with various versions of:
=if(A1<””,A1,””) - this was no where near complex enough to grab data from another worksheet with data points that drop off the list.

then tried this one:
=IF(('May 2012 Report'!A3:A226='June 2012 Report'!A3),'May 2012 Report'!D3: D226<"",'May 2012 Report'!$D$2:$D$225) (put space between : and D got a grin)

This one gives me a True/False statement in the first to cells then it keeps referring to empty cells.

Does not account for the change in my data in Column A: so records drop everything in D: even if A: in worksheet 1 does not correspond with data in worksheet 2.

Any suggestions to fix this