Comparing 2 Lists to Identify Differences

I am trying to maintain an employee spreadsheet that is updated weekly. I can cut and copy the new updated worksheet into the same workbook as the original, so that I am working within the same workbook, but if this does not matter let me know. I have multiple columns such as last name, first name, id no, etc...I was wanting to use the id no as it is the most specific. So in my old list I have a total of 264 entries, in my new list I have a total of 260 entries. I am wanting to compare the 2 lists and identify the 4 additional entries in my old list. Thanks for any help, Orracle