How to write JavaScript that launches immediately when user opens PDF file
We want to introduce new features with JS to our customers in our bills, offers, etc made in .pdf to leave feedback and use other interactive features.
I m new with both JS and Acrobat Pro too.
For testing purpose for myself and for now I want to acieve to get an alert (message box) immediately after opening my .pdf file.
Any advice how to do it in JavaScript Editor is welcome.

