Validating Data for Correctness during Entry
Just as you can limit the data displayed by your worksheets, you can limit the data entered into them as well. Setting validation rules for data entered into cells lets you catch many of the most common data-entry errors, such as entering values that are too small or too large or attempting to enter a word in a cell that requires a number. When you create a validation rule, you can also create a message to inform you and your colleagues what sort of data is expected for the cell.
Validate for Specific Requirements
Select the cells you want to validate.
On the Data tab, click the Data Validation button’s ...