How to print one specific Javascript variable in HTML?

Question

I want to ask how I can print a Javascript variable in HTML form (e.g. output it on the screen)?

Here is my JS code:

Answer 1

Set it to be the innerHTML or value of a html element:

var howLongIsThis = myPlayer.duration();
var displayEl = document.getElementById("duration");
displayEl.innerHTML = howLongIsThis;

or if you want in in a form field:

displayEl.value = howLongIsThis;