In this step, you will define the iiiTaxAmount virtual field to be calculated as 25% of the iiiSalary field:

1.  Select the iiiTaxAmount field in the list of Undefined virtuals.

2.  In the Details tab, enter the following:

 3.  Add the following code to Virtual Field Derivation

     #iiitaxamount := (#iiisalary / 100) * 25

     Change the code to use your initials.

     Your Details tab should now look like this:

4.  Now that its derivation has been defined, the iiiTaxAmount column will be listed under Read Virtuals. 

5.  Save the table definition.