<script type="text/javascript">

  function baseClass()

 {

     this.showMsg = function()

     {

         alert("baseClass::showMsg");

     }

     this.baseShowMsg = function()

     {

         alert("baseClass::baseShowMsg");

     }

 }

 baseClass.showMsg = function()

 {

     alert("baseClass::showMsg static");

 }

 function extendClass()

 {

     this.showMsg =function ()

     {

         alert("extendClass::showMsg");

     }

 }

 extendClass.showMsg = function()

 {

     alert("extendClass::showMsg static")

 }

 extendClass.prototype = new baseClass();

 var instance = new extendClass();

 instance.showMsg(); //显示extendClass::showMsg

 instance.baseShowMsg(); //显示baseClass::baseShowMsg

 instance.showMsg(); //显示extendClass::showMsg

 baseClass.showMsg.call(instance);//显示baseClass::showMsg static

 var baseinstance = new baseClass();

 baseinstance.showMsg.call(instance);//显示baseClass::showMsg

 </script>