Learn how to use a data validation control to allow users to select when to run multiple VBA procedures in Microsoft Excel.

To create a custom list, click the cell in which you want the list to appear. Click "Data Validation" on the Data tab and click "Data Validation." Choose "List" in the Allow box.

Duplicate entries may be valid -- but when they aren't, they can derail your summaries and totals. Use Excel's Validation feature to reject duplicate entries.