1 function log(msg){ 2     if (window["console"]){ 3         console.log(msg); 4     } 5 } 6 log("123456789!"); 7  8 (function($){ 9     alert(window.navigator.userAgent.toLowerCase() + ‘\t\n‘ +$.browser.version);10     //alert($.browser.version);11 })(jQuery);12 13 14 15 (function($){16     $.bbox={17         win:function(o){18             o=$.extend({19             name:‘skyer‘,20             age:20,21             sex:‘man‘22             },o||{});23             alert(o.name);24             alert(o.age);25         }26     }27 })(jQuery);28 29 $.bbox.win({age:28});30 31 32     $.fn.hoverClass = function (className) {33         var _self = this;34         _self.each(function (i) {35             _self.eq(i).mouseenter(function () {36                 $(this).addClass(className);37             });38             _self.eq(i).mouseleave(function () {39                 $(this).removeClass(className);40             });41         });42     return _self; 43     };44 45     $.fn.msg=function(txt){46         alert((txt || ""));47         return this48     }49     $("h1").msg("hello").css(‘color‘,‘#a00‘);