get the language of target element

jQuery.lang.js

/**
 * @param langid {String} optional
 * @return {jQuery} when langid is given.
 * @return langid {String} when langid is not given.
 **/
$.fn.lang = function(langid) {
    
    var elem = $(this);
    var	lang;

    function getLang(obj){
        if(obj.attr('lang')){
            lang = obj.attr('lang');
        }else if(obj.attr('xml:lang')){
            lang = obj.attr('xml:lang');
        }else{
            getLang(obj.parent())
        }
        return lang;
    }

    if(langid){
        return this.each(function(){
            elem.attr('lang',langid);
        });
    }else{
        return getLang(elem);
    }
};