Script to detect user language

detect_lang.php

function getDefaultLanguage() {
	if (isset($_SERVER["HTTP_ACCEPT_LANGUAGE"]))
		return parseDefaultLanguage($_SERVER["HTTP_ACCEPT_LANGUAGE"]);
	else
		return parseDefaultLanguage(NULL);
	}

function parseDefaultLanguage($http_accept, $deflang = "fr") {
	if( isset($http_accept) && strlen($http_accept) > 1 )  {
		// Split possible languages into array
		$x = explode(",",$http_accept);
		foreach ( $x as $val ) {
			//check for q-value and create associative array. No q-value means 1 by rule
			if( preg_match("/(.*);q=([0-1]{0,1}\.\d{0,4})/i",$val,$matches) ) {
				$lang[$matches[1]] = (float)$matches[2];
			} else {
				$lang[$val] = 1.0;
			}
		}
		//return default language (highest q-value)
		$qval = 0.0;
		foreach ($lang as $key => $value) {
			if ($value > $qval) {
				$qval = (float)$value;
				$deflang = $key;
			}
		}
   }
   return strtolower($deflang);
}