Should be easy, me thinks–insdljs.sty. I used it a few years ago.
Alas, neither acrotex nor insdljs seem to be part of texlive-2016. This gives me pause. It's been years that I have had to download anything from ctan. Usually, everything that's useful and recommended is already in texlive. So, now I am wondering – maybe there is a better solution by now?!
I also found some conflicting info here on txsx---does one use the "Tex Live Utility" to download and install ctan packages or not? How do I install CTAN packages on Mac OS with TexShop? suggests one can use TLU, which would be nice if this then gains the smarts to update the packages when outdated. alas, other txsx posts say it only is for packages on texlive, not more generelly on ctan.