find duplicate items and delete one

How to find duplicate items and delete one (row)?

In Excel 2000, we have one column with many items, some are duplicate. Now I can find duplicate items by using COUNTIF function. But there are so many items, over two thousand, with hundreds of duplicate items. I hope to delete one row (with larger address number) which has duplicated item.
How can I delete duplicate items quickly? By using a function, macro?
For example, cell B18 and B6 have duplicate items, now I want to delete row 18.