Targeting Media Queries in Javascript

script.js

function mediaqueryresponse(mql){
 if (mql.matches){ 
  alert("The condition " + mql.media + " has been met");
 }
 else{
  alert("Condition not met yet");
 }
}

var mql = window.matchMedia("screen and (max-width: 480px) and (orientation: portrait)");
mediaqueryresponse(mql) ;
mql.addListener(mediaqueryresponse);