var objB = new ClassB("red", "John");
<html>
<head>
<title>Example</title>
</head>
<body>
<script type="text/javascript">
function ClassA(sColor) {
this.color = sColor;
this.sayColor = function () {
alert(this.color);
};
}
function ClassB(sColor, sName) {
this.newMethod = ClassA;
this.newMethod(sColor);
delete this.newMethod;
this.name = sName;
this.sayName = function () {
alert(this.name);