The Add Fields command allows you to add fields to the current database, with the initial values in these fields set to missing values, which presumably will be replaced by other values as your work proceeds. When you select this command, the Add Fields dialog box appears.

Fields to create lists all of the fields in the Data Dictionary that are not in the current database. Select any number of fields to be added. ProVal will then add the specified fields to the current database, with all values equal to missing value. If the desired field is not listed, use the Database | Data Dictionary command to add it to the Data Dictionary.