Javascript in a PDF?

Question

I made up an editable PDF for students to request transcripts. Now, I want to constrain the input. For example, I want only numbers for their ID number, and I want only letters

Answer 1

Yes, the Adobe Acrobat Reader supports hosting JavaScript for uses such as field validation.

Here's some reference material:

http://www.adobe.com/devnet/acrobat/javascript.html

and some tutorials:

http://www.evermap.com/javascript.asp

http://www.pdfscripting.com/

AFAIK, you will need the full (Pro) version of Acrobat to write the scripts.