After doing this, opened the index.htm file for the classic site in a browser and it takes me to the mobile site in the browser. Great! When I put the dimension back to "less than 699" or: if (screen.width <=699) if reverts back to desktop site
Which gives us proof that the code works and a working example

The next step is then to check that the code is executed properly on the mobile device and that JS is enabled on it. (see Sledger's link)

If this does not work on the device in its default setup then it's probably a non-starter.

http://resumeidentity.com/mobile seems to work OK