$lang_array = array( "en" => "en",
"fr" => "fr",
"it" => "it",
"es" => "es",
"pt" => "pt",
"ja" => "jp" );
$loc = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'],0,2);
if (!in_array($loc, $lang_array[0])) $loc = "en";
if (!in_array($loc, array_keys($lang_array))) $loc = "en";