The easiest way to detect IE in JavaScript

detectIE.js

/* 
  From: http://devoracles.com/the-best-method-to-check-for-internet-explorer-in-javascript

  "I declared a new variable, called IE, which has the value a comment block followed by ‘false‘.
  The above variable will be understood by IE: var IE = !false, because Internet Explorer uses 
  JScript — a Javascript-like dialect of the standard ECMAScript — instead of Javascript which is 
  used by all the other browsers. JScript can parse the comments, just like Internet Explorer (see 
  conditional HTML comments post). This is a unique feature of IE, none of the other browsers can do it, 
  so Firefox, Chrome, Safari, Opera, all will understand the above declaration as IE = false."
*/

var IE = /*@cc_on!@*/false;

if (IE) {
  // do things for IE
}
else {
  // do things for other browsers
}

Please note that this only works for IE 10 and older.