Redirecting to a Different Language Directory

[M40_]

I'm working on a multi language website and I use directories like www.mysite.com/en/, www.mysite.com/es/, www.mysite.com/de/ to hold the different language versions.

I'd like the user to be able to change the language from every page in the website and on changing the language to be redirected to the exactly the same page but in the newly chosen language.

For example if the user is at www.mysite.com/en/products/product_name.php he/she should be able to chose a different language from there and if he/she does so, for example if he/she choses Spanish, he should be redirected to www.mysite.com/es/products/product_name.php

What would be the best way to achieve that?

Thank you!

[Cups]

make a page called redirect.php

When user selects a language, from say a drop down, then send to redirect.php.

Send along with the request

the url of this page "/en/products/prod1.php"
The selected lang code es.

Get redirect.php to ;

check the incoming vars!
set a new cookie with lang=es
chop off the /en/ from the incoming url
add /es/ to it
redirect the user.