Hello
I don't know how to change the language to a web site without reloading, by clicking the flag . I suppose that must insert the text to php tables or to a database?

I have seen that the url changes to " .../index.php?newlang=greek "

Any ideas or example to do that ?

Tnx

To change the language without reloading, you must have access to the translated content or a plugin extension to all browsers that facilitates translation. Assuming you're not planning on writing those plugins for this task, you have (as far as I see) 2 options for gaining access to the content:

1) Have it all on the page for each language and then toggle the visibility of the proper language when the user selects their language.
2) Use Ajax techniques to fetch and replace translated content.

Both techniques require javascript. The first technique will be problematic if you need to change page encoding and will require unnecessarily-long page load times. The second technique will be a bit more javascript intensive, depending on how picky you want the script to be.

I recommend just loading the new page.