how can I trace wheel event in html with javascript?

I have want to trace wheel – but page isn’t scroll becase my content is fit for page.
also I need to Know wheel rolling up or down ?

This is my code ,it just work when page is scrollable but (my page isn’t)

function myFunction() { // put this fun on a event of element.
    if (document.body.scrollTop > 50) 
     {
      console.log(document.body.scrollTop);
     } 
 }