How do I specify the following requirement in my html?
When the computer has access to Internet, the source of MathJax.js is https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js;
When it is offline, and the system is Linux, the source is /MathJax/MathJax.js
; if the system is Windows, it is /C:/MathJax/MathJax.js
. (It would be even better if I can use environment variable in the local path.)