How do add a tick box to terms & conditions

I recently added a question about adding a "tick" box to a document to confirm the customer accepts my Terms and Conditions.  After doing a search I managed to sort this out, however, the problem I now have is, the Terms and Conditions are not directly "typed" onto a page of my website, but are uploaded to the site in a PDF format.  What I'd like to be able to do, is make sure when the "tick" box is ticked, this not only directs customers to the correct page of my website (which I've managed to do), but to also automatically open the relevant document.  Hope this makes sense.  I need someone to advise the code of how to do this.  Please help, I've managed everything so far, but this is a bit technical and I have no idea about writing codes.  Thank you.

I think you can make this to happen by using the Terms and Condition widgets , in there you can establish the URL where the PDF is so when they tick on the box, they can also click on the link to the PDF.

I hope this helps to sort out the issue. Otherwise let us know.