1//The fancy word for the ability of multiple object types to 
2//implement the same functionality is polymorphism -MDN

1<script>  
2class A  
3  {  
4     display()  
5    {  
6      document.writeln("A is invoked");  
7    }  
8  }  
9class B extends A  
10  {  
11  }  
12var b=new B();  
13b.display();  
14</script>