Url link to a file

var url:String = “References.pdf”;
var request:URLRequest = new URLRequest(url);
navigateToURL(request, ‘_blank’);

that’s what i have currently.

It worked fine in osx on safari. It opened the pdf in the browser.

but on a pc with firefox I dont think it has the same in browser pdf capabilities,

How do I just initiate a download prompt or something?