Any form you create that requires calculations is likely to require custom calculation scripts. The options you have available with preset calculation formulas are limited to simple multiplication and addition. Other kind of calculation you need requires writing a script.

To write a calculation script

1. Ouvrir le PDF dans Nitro Pro
2. On the Forms ribbon, in the Form Fields group, click Text Field
3. Select the text field to edit
4. Right-click and select Properties
5. Click the Calculate tab
6. Click the Custom calculation script option, and then click the Edit button

7. Type the code for your script. In the example below, a simple routine is created to calculate sales tax at a 7.25 % rate. The code used is:

   var f = this.getField(subtotal);
   event.value = Math.round(f.value * 7.25)/100;
   

8. Cliquez sur d'accord