Detect the version of Internet Explorer (not Edge)

getIEVersion.js

/**
 * Get IE Version
 * @returns {integer} Version of Internet Explorer, or 0
 */
function GetIEVersion() {
  var sAgent = window.navigator.userAgent;
  var Idx = sAgent.indexOf("MSIE");

  // If IE, return version number.
  if (Idx > 0) 
    return parseInt(sAgent.substring(Idx+ 5, sAgent.indexOf(".", Idx)));

  // If IE 11 then look for Updated user agent string.
  else if (!!navigator.userAgent.match(/Trident\/7\./)) 
    return 11;

  else
    return 0; //It is not IE
}