Triggering a function with external text

Hi,

It’s been a while since the last time I was on this forum - a nice long holiday to Italy is the reason to that. Now, my question is, is it possible to trigger a function via externally loaded text?

So, let’s say I have some kind of a news reader, and I wan’t a couple of buttons in there: “next” & “previous”. Is there some kind of tag I could use, to make some of the extrenally loaded text, to trigger my “next” & “previous” functions - and if there is, then, what would that tag look like?