Multi-language problem, how to display the appropriate language by selecting the drop-down list

Multi-lingual problem, I now use gettext many languages, there are several problems do not know how to deal with:

One. How to display the appropriate language by selecting the drop-down list. (directly by selecting the drop-down list to display the appropriate language, do not click the button, etc.)

Two. Sometimes after querying the data and then switching languages, how to run the state of the query.

Reply to discussion (solution)

1. Bind the Select control to the OnChange event, and then do the appropriate action.
2. Session Pass Value

JORDAN102, can you give me a sample?

One. onchange event How to get the page to the new language, get the URL of the current page, there would have been Lang's parameters
My link is www.1234756.com?lang=en

Two. Can you give me a concrete example?

Thank you xuzuning greatly. How to pass the value of the session, I mean through the drop-down list box such as your post query, you can write: session_start (); if (Isset ($_session[' key ')) {$key =$_session[' key ') ;} else{$key =$_post[' key ']; $_session[' key ']=$_post[' key ';} ......................... 