Specifying a Data Validation Error Message

If someone tries to enter a value into a cell that has a data validation rule defined, and that value is outside the bounds of the validation rule you have specified, they will see an error message. Excel allows you to modify the default error message to provide meaningful information to the user. When used in conjunction with the input message, data validation becomes a very powerful tool in developing worksheets to be used by others.

1. Select the cell for which you want to define the messages.
2. Display the Data Validation dialog box. (If you are using a version of Excel prior to Excel 2007, click Data | Validation. If you are using Excel 2007, display the Data tab of the ribbon and click the Data Validation tool.)
3. Set any data validation rules desired.
4. Click on the Error Alert tab. (Click here to see a related figure.)
5. Use the Style drop-down list to select different icons that should appear in the error message dialog box.
6. Enter a message in both the Title and Error Message fields, as desired.
7. Click on the OK button.

When the user enters an incorrect value and presses Enter or tries to move to another cell, a dialog box appears with your message.

You should realize that what the user can do once the error message dialog box is displayed is dependent on which error style you chose in step 5. For instance, if you choose the Stop style, the user can only retry their entry or cancel it. (In other words, you are forcing them to put in the right value.) If you choose the Warning style, then they are notified of their error, but they can still continue with the wrong value in the cell. Finally, the Information style is the most gentle reminder of all, and the user can still go on and accept the incorrect entry.