I want my website to have two languages. One is English and one is Japanese. I like to have
www.domain.com to be english and
www.domain.com/ja/ to be Japanese.
Now, If a user is using a Japanese Operating System, I want him/her to be automatically redirected to
www.domain.com/ja/ (a Japanese version). If a user is using an ordinary English OS, then it stays the same as
www.domain.com.
One good example of this I found is Skype.com (the older website). However, I don't know what HTML code I should use. Kindly tell me what kind of code I should put and where? And I want it to be Google and Search Engine friendly.
Thanks