日志输出 jquery扩展

function log(msg){
    if (window["console"]){
        console.log(msg);
    }
}
log("123456789!");

(function($){
    alert(window.navigator.userAgent.toLowerCase() + '	
' +$.browser.version);
    //alert($.browser.version);
})(jQuery);



(function($){
    $.bbox={
        win:function(o){
            o=$.extend({
            name:'skyer',
            age:20,
            sex:'man'
            },o||{});
            alert(o.name);
            alert(o.age);
        }
    }
})(jQuery);

$.bbox.win({age:28});


    $.fn.hoverClass = function (className) {
        var _self = this;
        _self.each(function (i) {
            _self.eq(i).mouseenter(function () {
                $(this).addClass(className);
            });
            _self.eq(i).mouseleave(function () {
                $(this).removeClass(className);
            });
        });
    return _self; 
    };

    $.fn.msg=function(txt){
        alert((txt || ""));
        return this
    }
    $("h1").msg("hello").css('color','#a00');