I am using a workbook with thousands of lines. Some data is very old and
either missing or or out dated. In particular I am looking to find the
ship_date for each project_id. There is another worksheet that has about 80%
overlap with my workbook. How can i get the good ship_date information from
the other workbook into my workbook, and how can I see which project_ids are
missing in my workbook so I can add those rows?

ken