Calculating field based on the value of another field

[aug4570]

Hello,

Just wondered how to calculate the value of one field based on the value of another. Example: If Field1 value is 'A' then Field2's value is 5%(Field3 + Field4). If Field1 value is 'B' then Field2's value is just 5% of Field3.

Thanks for the help

 

[swampBoogie]

use iif

iif(field1 = 'A',0.05*(field3+field4),
iif(field1 = 'B', 0.05*field3),4711)

What should it be if field1 is neither A or B? I put 4711 for that case.