IE Browser Version Detection by Nimesh as modified by Mehdi Raash, 2018/05/02. (Further modified by MDJ 2018/08/22.)
This script detects the version number for IE browsers only. For other browsers, it returns "undefined".
To examine the details of this browser detection method, simply right-click this page and then select "View Page Source" (in Firefox - other browsers similar).
M.D.J. 2018/08/22
Nimesh and Raash, Mehdi (2018) https://stackoverflow.com/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser.