First off I know that a responsive site is no. 1 but at the time being that unfortunately is not an option! I also have very javascript coding skills.
I need to detect w
Your solution looks good just add a check for screen width as well which is 970px for ipad or tabs, 768px for mobile devices(smartphones) and greater than 970px for desktop version.
As it seems you cannot use media queries as you want to redirect based on devices else media queries are the best way to do responsive design.
You can have a look at below link as well.
https://css-tricks.com/snippets/javascript/redirect-mobile-devices/