iOS, Android detection and position fixed

gistfile1.js

var ua = navigator.userAgent;
    var checker = {
      iphone: ua.match(/(iPhone|iPod|iPad)/),
      blackberry: ua.match(/BlackBerry/),
      android: ua.match(/Android/)
    };
  
  /*Check if device runs iOS 5 or higher*/
  fiveorhigher = navigator.userAgent.match(/[5-9]_[0-9]/) !== null;
  if(console) {console.log(fiveorhigher);}
  //alert(navigator.userAgent);
  
  /*Check if device runs Android 3 or higher*/
  threeorhigher = navigator.userAgent.match(/[3-9].[0-9].[0-9]/) !== null;
  if(console) {console.log(threeorhigher);}
  //alert(navigator.userAgent);
  
  // position fixed hack for ios < 5.0 and android < 3.0.0
  window.onscroll = function() {
    if( ((navigator.platform == 'iPad' || navigator.platform == 'iPhone' || navigator.platform == 'iPod') && !fiveorhigher) || ((checker.android) ) && !threeorhigher ) {
      document.getElementById('containerFixed').style.top =
     (window.pageYOffset + window.innerHeight - 160) + 'px';
    }
  };//window.pageYOffset +