Questions about development a form

[Kota-M]

Hello, nice to meet you.
I have been implementing my form with the plugin, and would like to ask some "how to" questions.

1. I read the section of "The afterValidate event", but even if I put the code in config file, the validation does not work.
   Where should I put the validation code?

2. My auto-respond email is like this;

• Name: Kota
• Email: kota@.....
• Phone: 647-xxx-xxxx
• fileNumber: 1234567

Is it possible to replace "fileNumber" with "File Number"?
It is from the field ID, but it seems not possible to contain a space.